[PATCH v2 0/2] Add more DAP launch parameters

[PATCH v2 0/2] Add more DAP launch parameters

[Tom Tromey]

This series adds some more Python attributes (and methods), and then
uses these to implement some new launch parameters for DAP.

Inferior.main_name is added but not used.  I plan to use this to
implement a "stop at main" launch parameter, after we work out a few
details.  Meanwhile it seemed harmless and potentially useful.

Tom

---
Changes in v2:
- Updated per reviews
- Link to v1: https://inbox.sourceware.org/gdb-patches/20230509-dap-args-v1-0-16b5f0aa5cd6@adacore.com

---
Tom Tromey (2):
      Add attributes and methods to gdb.Inferior
      Add "args" and "env" parameters to DAP launch request

 gdb/NEWS                                 |  10 ++
 gdb/doc/gdb.texinfo                      |  13 ++-
 gdb/doc/python.texi                      |  44 ++++++++
 gdb/python/lib/gdb/dap/launch.py         |  20 +++-
 gdb/python/py-inferior.c                 | 169 +++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.ada/py_range.exp       |   4 +
 gdb/testsuite/gdb.dap/args-env.c         |  28 +++++
 gdb/testsuite/gdb.dap/args-env.exp       |  90 ++++++++++++++++
 gdb/testsuite/gdb.python/py-inferior.exp |  36 +++++++
 gdb/testsuite/lib/dap-support.exp        |  39 +++++--
 10 files changed, 441 insertions(+), 12 deletions(-)
---
base-commit: 80d4e113d7b9af8a5a36e5ea4399bca86050784f
change-id: 20230509-dap-args-596e21f0b48d

Best regards,
-- 
Tom Tromey <tromey@adacore.com>

[PATCH v2 1/2] Add attributes and methods to gdb.Inferior

[Tom Tromey]

This adds two new attributes and three new methods to gdb.Inferior.

The attributes let Python code see the command-line arguments and the
name of "main".  Argument setting is also supported.

The methods let Python code manipulate the inferior's environment
variables.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
---
 gdb/NEWS                                 |  10 ++
 gdb/doc/python.texi                      |  44 ++++++++
 gdb/python/py-inferior.c                 | 169 +++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.ada/py_range.exp       |   4 +
 gdb/testsuite/gdb.python/py-inferior.exp |  36 +++++++
 5 files changed, 263 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index b82114d80b0..19bbb41c32f 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -192,6 +192,16 @@ info main
      - Changes are backwards compatible, the older API can still be
        used to disassemble instructions without styling.
 
+  ** gdb.Inferior now has a new "arguments" attribute.  This holds the
+     command-line arguments to the inferior, if known.
+
+  ** gdb.Inferior now has a new "main_name" attribute.  This holds the
+     name of the inferior's "main", if known.
+
+  ** gdb.Inferior now has new methods "clear_env", "set_env", and
+     "unset_env".  These can be used to modify the inferior's
+     environment before it is started.
+
 *** 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 5d714ee1ca3..4bdd52466d0 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -3446,10 +3446,30 @@ Boolean signaling whether the inferior was created using `attach', or
 started by @value{GDBN} itself.
 @end defvar
 
+@defvar Inferior.main_name
+A string holding the name of this inferior's ``main'' function, if it
+can be determined.  If the name of main is not known, this is
+@code{None}.
+@end defvar
+
 @defvar Inferior.progspace
 The inferior's program space.  @xref{Progspaces In Python}.
 @end defvar
 
+@defvar Inferior.arguments
+The inferior's command line arguments, if known.  This corresponds to
+the @code{set args} and @code{show args} commands.  @xref{Arguments}.
+
+When accessed, the value is a string holding all the arguments.  The
+contents are quoted as they would be when passed to the shell.  If
+there are no arguments, the value is @code{None}.
+
+Either a string or a sequence of strings can be assigned to this
+attribute.  When a string is assigned, it is assumed to have any
+necessary quoting for the shell; when a sequence is assigned, the
+quoting is applied by @value{GDBN}.
+@end defvar
+
 A @code{gdb.Inferior} object has the following methods:
 
 @defun Inferior.is_valid ()
@@ -3517,6 +3537,30 @@ the same functionality, but use of @code{Inferior.thread_from_thread_handle}
 is deprecated.
 @end defun
 
+
+The environment that will be passed to the inferior can be changed
+from Python by using the following methods.  These methods only take
+effect when the inferior is started -- they will not affect an
+inferior that is already executing.
+
+@findex Inferior.clear_env
+@defun Inferior.clear_env ()
+Clear the current environment variables that will be passed to this
+inferior.
+@end defun
+
+@findex Inferior.set_env
+@defun Inferior.set_env (name, value)
+Set the environment variable @var{name} to have the indicated value.
+Both parameters must be strings.
+@end defun
+
+@findex Inferior.unset_env
+@defun Inferior.unset_env (name)
+Unset the environment variable @var{name}.  @var{name} must be a
+string.
+@end defun
+
 @node Events In Python
 @subsubsection Events In Python
 @cindex inferior events in Python
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index 982d0f803a0..8c4871dfa89 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -770,6 +770,162 @@ infpy_repr (PyObject *obj)
 			       inf->num, inf->pid);
 }
 
+/* Implement clear_env.  */
+
+static PyObject *
+infpy_clear_env (PyObject *obj)
+{
+  inferior_object *self = (inferior_object *) obj;
+
+  INFPY_REQUIRE_VALID (self);
+
+  self->inferior->environment.clear ();
+  Py_RETURN_NONE;
+}
+
+/* Implement set_env.  */
+
+static PyObject *
+infpy_set_env (PyObject *obj, PyObject *args, PyObject *kw)
+{
+  inferior_object *self = (inferior_object *) obj;
+  INFPY_REQUIRE_VALID (self);
+
+  const char *name, *val;
+  static const char *keywords[] = { "name", "value", nullptr };
+
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "ss", keywords,
+					&name, &val))
+    return nullptr;
+
+  self->inferior->environment.set (name, val);
+  Py_RETURN_NONE;
+}
+
+/* Implement unset_env.  */
+
+static PyObject *
+infpy_unset_env (PyObject *obj, PyObject *args, PyObject *kw)
+{
+  inferior_object *self = (inferior_object *) obj;
+  INFPY_REQUIRE_VALID (self);
+
+  const char *name;
+  static const char *keywords[] = { "name", nullptr };
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s", keywords, &name))
+    return nullptr;
+
+  self->inferior->environment.unset (name);
+  Py_RETURN_NONE;
+}
+
+/* Getter for "arguments".  */
+
+static PyObject *
+infpy_get_args (PyObject *self, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  INFPY_REQUIRE_VALID (inf);
+
+  const std::string &args = inf->inferior->args ();
+  if (args.empty ())
+    Py_RETURN_NONE;
+
+  return host_string_to_python_string (args.c_str ()).release ();
+}
+
+/* Setter for "arguments".  */
+
+static int
+infpy_set_args (PyObject *self, PyObject *value, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  if (!inf->inferior)
+    {
+      PyErr_SetString (PyExc_RuntimeError, _("Inferior no longer exists."));
+      return -1;
+    }
+
+  if (value == nullptr)
+    {
+      PyErr_SetString (PyExc_TypeError,
+		       _("Cannot delete 'arguments' attribute."));
+      return -1;
+    }
+
+  if (gdbpy_is_string (value))
+    {
+      gdb::unique_xmalloc_ptr<char> str = python_string_to_host_string (value);
+      if (str == nullptr)
+	return -1;
+      inf->inferior->set_args (std::string (str.get ()));
+    }
+  else if (PySequence_Check (value))
+    {
+      std::vector<gdb::unique_xmalloc_ptr<char>> args;
+      Py_ssize_t len = PySequence_Size (value);
+      if (len == -1)
+	return -1;
+      for (Py_ssize_t i = 0; i < len; ++i)
+	{
+	  gdbpy_ref<> item (PySequence_ITEM (value, i));
+	  if (item == nullptr)
+	    return -1;
+	  gdb::unique_xmalloc_ptr<char> str
+	    = python_string_to_host_string (item.get ());
+	  if (str == nullptr)
+	    return -1;
+	  args.push_back (std::move (str));
+	}
+      std::vector<char *> argvec;
+      for (const auto &arg : args)
+	argvec.push_back (arg.get ());
+      gdb::array_view<char * const> view (argvec.data (), argvec.size ());
+      inf->inferior->set_args (view);
+    }
+  else
+    {
+      PyErr_SetString (PyExc_TypeError,
+		       _("string or sequence required for 'arguments'"));
+      return -1;
+    }
+  return 0;
+}
+
+/* Getter for "main_name".  */
+
+static PyObject *
+infpy_get_main_name (PyObject *self, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  INFPY_REQUIRE_VALID (inf);
+
+  const char *name = nullptr;
+  try
+    {
+      /* This is unfortunate but the implementation of main_name can
+	 reach into memory.  */
+      scoped_restore_current_inferior restore_inferior;
+      set_current_inferior (inf->inferior);
+
+      scoped_restore_current_program_space restore_current_progspace;
+      set_current_program_space (inf->inferior->pspace);
+
+      name = main_name ();
+    }
+  catch (const gdb_exception &except)
+    {
+      /* We can just ignore this.  */
+    }
+
+  if (name == nullptr)
+    Py_RETURN_NONE;
+
+  return host_string_to_python_string (name).release ();
+}
 
 static void
 infpy_dealloc (PyObject *obj)
@@ -844,6 +1000,8 @@ GDBPY_INITIALIZE_FILE (gdbpy_initialize_inferior);
 
 static gdb_PyGetSetDef inferior_object_getset[] =
 {
+  { "arguments", infpy_get_args, infpy_set_args,
+    "Arguments to this program.", nullptr },
   { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
   { "connection", infpy_get_connection, NULL,
     "The gdb.TargetConnection for this inferior.", NULL },
@@ -854,6 +1012,8 @@ static gdb_PyGetSetDef inferior_object_getset[] =
   { "was_attached", infpy_get_was_attached, NULL,
     "True if the inferior was created using 'attach'.", NULL },
   { "progspace", infpy_get_progspace, NULL, "Program space of this inferior" },
+  { "main_name", infpy_get_main_name, nullptr,
+    "Name of 'main' function, if known.", nullptr },
   { NULL }
 };
 
@@ -889,6 +1049,15 @@ Return thread object corresponding to thread handle." },
   { "architecture", (PyCFunction) infpy_architecture, METH_NOARGS,
     "architecture () -> gdb.Architecture\n\
 Return architecture of this inferior." },
+  { "clear_env", (PyCFunction) infpy_clear_env, METH_NOARGS,
+    "clear_env () -> None\n\
+Clear environment of this inferior." },
+  { "set_env", (PyCFunction) infpy_set_env, METH_VARARGS | METH_KEYWORDS,
+    "set_env (name, value) -> None\n\
+Set an environment variable of this inferior." },
+  { "unset_env", (PyCFunction) infpy_unset_env, METH_VARARGS | METH_KEYWORDS,
+    "unset_env (name) -> None\n\
+Unset an environment of this inferior." },
   { NULL }
 };
 
diff --git a/gdb/testsuite/gdb.ada/py_range.exp b/gdb/testsuite/gdb.ada/py_range.exp
index 2972db21827..833493bad95 100644
--- a/gdb/testsuite/gdb.ada/py_range.exp
+++ b/gdb/testsuite/gdb.ada/py_range.exp
@@ -42,3 +42,7 @@ gdb_test "python print(gdb.parse_and_eval('si').type)" \
     "foo\\.small_integer" "print type"
 gdb_test "python print(gdb.parse_and_eval('si').type.name)" \
     "foo\\.small_integer" "print type name"
+
+gdb_test "python print(gdb.selected_inferior().main_name)" \
+    "_ada_foo" \
+    "print main name"
diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
index 424050a6166..58deece5d5f 100644
--- a/gdb/testsuite/gdb.python/py-inferior.exp
+++ b/gdb/testsuite/gdb.python/py-inferior.exp
@@ -342,3 +342,39 @@ with_test_prefix "architecture" {
 	"True" \
 	"inferior architecture matches frame architecture"
 }
+
+gdb_test "python print(gdb.selected_inferior().main_name)" \
+    "main" \
+    "print main name"
+
+gdb_test_no_output "set args x y z"
+gdb_test "python print(gdb.selected_inferior().arguments)" \
+    "x y z" \
+    "print arguments"
+
+gdb_test_no_output "python gdb.selected_inferior().arguments = 'a b c'" \
+    "set arguments from string"
+gdb_test "show args" \
+    [string_to_regexp "Argument list to give program being debugged when it is started is \"a b c\"."] \
+    "show args from string"
+
+gdb_test_no_output "python gdb.selected_inferior().arguments = \['a', 'b c'\]" \
+    "set arguments from list"
+gdb_test "show args" \
+    [string_to_regexp "Argument list to give program being debugged when it is started is \"a b\\ c\"."] \
+    "show args from list"
+
+gdb_test_no_output "python gdb.selected_inferior().clear_env()" \
+    "clear environment"
+gdb_test_no_output "show environment"
+
+gdb_test_no_output "python gdb.selected_inferior().set_env('DEI', 'value')" \
+    "set environment variable"
+gdb_test "show environment" \
+    "DEI=value" \
+    "examine environment variable"
+
+gdb_test_no_output "python gdb.selected_inferior().unset_env('DEI')" \
+    "unset environment variable"
+gdb_test_no_output "show environment" \
+    "environment is empty again"

-- 
2.40.0

Re: [PATCH v2 1/2] Add attributes and methods to gdb.Inferior

[Andrew Burgess]

Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

> This adds two new attributes and three new methods to gdb.Inferior.
>
> The attributes let Python code see the command-line arguments and the
> name of "main".  Argument setting is also supported.
>
> The methods let Python code manipulate the inferior's environment
> variables.
>
> Reviewed-By: Eli Zaretskii <eliz@gnu.org>

LGTM.

Reviewed-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew

> ---
>  gdb/NEWS                                 |  10 ++
>  gdb/doc/python.texi                      |  44 ++++++++
>  gdb/python/py-inferior.c                 | 169 +++++++++++++++++++++++++++++++
>  gdb/testsuite/gdb.ada/py_range.exp       |   4 +
>  gdb/testsuite/gdb.python/py-inferior.exp |  36 +++++++
>  5 files changed, 263 insertions(+)
>
> diff --git a/gdb/NEWS b/gdb/NEWS
> index b82114d80b0..19bbb41c32f 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -192,6 +192,16 @@ info main
>       - Changes are backwards compatible, the older API can still be
>         used to disassemble instructions without styling.
>  
> +  ** gdb.Inferior now has a new "arguments" attribute.  This holds the
> +     command-line arguments to the inferior, if known.
> +
> +  ** gdb.Inferior now has a new "main_name" attribute.  This holds the
> +     name of the inferior's "main", if known.
> +
> +  ** gdb.Inferior now has new methods "clear_env", "set_env", and
> +     "unset_env".  These can be used to modify the inferior's
> +     environment before it is started.
> +
>  *** 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 5d714ee1ca3..4bdd52466d0 100644
> --- a/gdb/doc/python.texi
> +++ b/gdb/doc/python.texi
> @@ -3446,10 +3446,30 @@ Boolean signaling whether the inferior was created using `attach', or
>  started by @value{GDBN} itself.
>  @end defvar
>  
> +@defvar Inferior.main_name
> +A string holding the name of this inferior's ``main'' function, if it
> +can be determined.  If the name of main is not known, this is
> +@code{None}.
> +@end defvar
> +
>  @defvar Inferior.progspace
>  The inferior's program space.  @xref{Progspaces In Python}.
>  @end defvar
>  
> +@defvar Inferior.arguments
> +The inferior's command line arguments, if known.  This corresponds to
> +the @code{set args} and @code{show args} commands.  @xref{Arguments}.
> +
> +When accessed, the value is a string holding all the arguments.  The
> +contents are quoted as they would be when passed to the shell.  If
> +there are no arguments, the value is @code{None}.
> +
> +Either a string or a sequence of strings can be assigned to this
> +attribute.  When a string is assigned, it is assumed to have any
> +necessary quoting for the shell; when a sequence is assigned, the
> +quoting is applied by @value{GDBN}.
> +@end defvar
> +
>  A @code{gdb.Inferior} object has the following methods:
>  
>  @defun Inferior.is_valid ()
> @@ -3517,6 +3537,30 @@ the same functionality, but use of @code{Inferior.thread_from_thread_handle}
>  is deprecated.
>  @end defun
>  
> +
> +The environment that will be passed to the inferior can be changed
> +from Python by using the following methods.  These methods only take
> +effect when the inferior is started -- they will not affect an
> +inferior that is already executing.
> +
> +@findex Inferior.clear_env
> +@defun Inferior.clear_env ()
> +Clear the current environment variables that will be passed to this
> +inferior.
> +@end defun
> +
> +@findex Inferior.set_env
> +@defun Inferior.set_env (name, value)
> +Set the environment variable @var{name} to have the indicated value.
> +Both parameters must be strings.
> +@end defun
> +
> +@findex Inferior.unset_env
> +@defun Inferior.unset_env (name)
> +Unset the environment variable @var{name}.  @var{name} must be a
> +string.
> +@end defun
> +
>  @node Events In Python
>  @subsubsection Events In Python
>  @cindex inferior events in Python
> diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
> index 982d0f803a0..8c4871dfa89 100644
> --- a/gdb/python/py-inferior.c
> +++ b/gdb/python/py-inferior.c
> @@ -770,6 +770,162 @@ infpy_repr (PyObject *obj)
>  			       inf->num, inf->pid);
>  }
>  
> +/* Implement clear_env.  */
> +
> +static PyObject *
> +infpy_clear_env (PyObject *obj)
> +{
> +  inferior_object *self = (inferior_object *) obj;
> +
> +  INFPY_REQUIRE_VALID (self);
> +
> +  self->inferior->environment.clear ();
> +  Py_RETURN_NONE;
> +}
> +
> +/* Implement set_env.  */
> +
> +static PyObject *
> +infpy_set_env (PyObject *obj, PyObject *args, PyObject *kw)
> +{
> +  inferior_object *self = (inferior_object *) obj;
> +  INFPY_REQUIRE_VALID (self);
> +
> +  const char *name, *val;
> +  static const char *keywords[] = { "name", "value", nullptr };
> +
> +  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "ss", keywords,
> +					&name, &val))
> +    return nullptr;
> +
> +  self->inferior->environment.set (name, val);
> +  Py_RETURN_NONE;
> +}
> +
> +/* Implement unset_env.  */
> +
> +static PyObject *
> +infpy_unset_env (PyObject *obj, PyObject *args, PyObject *kw)
> +{
> +  inferior_object *self = (inferior_object *) obj;
> +  INFPY_REQUIRE_VALID (self);
> +
> +  const char *name;
> +  static const char *keywords[] = { "name", nullptr };
> +  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s", keywords, &name))
> +    return nullptr;
> +
> +  self->inferior->environment.unset (name);
> +  Py_RETURN_NONE;
> +}
> +
> +/* Getter for "arguments".  */
> +
> +static PyObject *
> +infpy_get_args (PyObject *self, void *closure)
> +{
> +  inferior_object *inf = (inferior_object *) self;
> +
> +  INFPY_REQUIRE_VALID (inf);
> +
> +  const std::string &args = inf->inferior->args ();
> +  if (args.empty ())
> +    Py_RETURN_NONE;
> +
> +  return host_string_to_python_string (args.c_str ()).release ();
> +}
> +
> +/* Setter for "arguments".  */
> +
> +static int
> +infpy_set_args (PyObject *self, PyObject *value, void *closure)
> +{
> +  inferior_object *inf = (inferior_object *) self;
> +
> +  if (!inf->inferior)
> +    {
> +      PyErr_SetString (PyExc_RuntimeError, _("Inferior no longer exists."));
> +      return -1;
> +    }
> +
> +  if (value == nullptr)
> +    {
> +      PyErr_SetString (PyExc_TypeError,
> +		       _("Cannot delete 'arguments' attribute."));
> +      return -1;
> +    }
> +
> +  if (gdbpy_is_string (value))
> +    {
> +      gdb::unique_xmalloc_ptr<char> str = python_string_to_host_string (value);
> +      if (str == nullptr)
> +	return -1;
> +      inf->inferior->set_args (std::string (str.get ()));
> +    }
> +  else if (PySequence_Check (value))
> +    {
> +      std::vector<gdb::unique_xmalloc_ptr<char>> args;
> +      Py_ssize_t len = PySequence_Size (value);
> +      if (len == -1)
> +	return -1;
> +      for (Py_ssize_t i = 0; i < len; ++i)
> +	{
> +	  gdbpy_ref<> item (PySequence_ITEM (value, i));
> +	  if (item == nullptr)
> +	    return -1;
> +	  gdb::unique_xmalloc_ptr<char> str
> +	    = python_string_to_host_string (item.get ());
> +	  if (str == nullptr)
> +	    return -1;
> +	  args.push_back (std::move (str));
> +	}
> +      std::vector<char *> argvec;
> +      for (const auto &arg : args)
> +	argvec.push_back (arg.get ());
> +      gdb::array_view<char * const> view (argvec.data (), argvec.size ());
> +      inf->inferior->set_args (view);
> +    }
> +  else
> +    {
> +      PyErr_SetString (PyExc_TypeError,
> +		       _("string or sequence required for 'arguments'"));
> +      return -1;
> +    }
> +  return 0;
> +}
> +
> +/* Getter for "main_name".  */
> +
> +static PyObject *
> +infpy_get_main_name (PyObject *self, void *closure)
> +{
> +  inferior_object *inf = (inferior_object *) self;
> +
> +  INFPY_REQUIRE_VALID (inf);
> +
> +  const char *name = nullptr;
> +  try
> +    {
> +      /* This is unfortunate but the implementation of main_name can
> +	 reach into memory.  */
> +      scoped_restore_current_inferior restore_inferior;
> +      set_current_inferior (inf->inferior);
> +
> +      scoped_restore_current_program_space restore_current_progspace;
> +      set_current_program_space (inf->inferior->pspace);
> +
> +      name = main_name ();
> +    }
> +  catch (const gdb_exception &except)
> +    {
> +      /* We can just ignore this.  */
> +    }
> +
> +  if (name == nullptr)
> +    Py_RETURN_NONE;
> +
> +  return host_string_to_python_string (name).release ();
> +}
>  
>  static void
>  infpy_dealloc (PyObject *obj)
> @@ -844,6 +1000,8 @@ GDBPY_INITIALIZE_FILE (gdbpy_initialize_inferior);
>  
>  static gdb_PyGetSetDef inferior_object_getset[] =
>  {
> +  { "arguments", infpy_get_args, infpy_set_args,
> +    "Arguments to this program.", nullptr },
>    { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
>    { "connection", infpy_get_connection, NULL,
>      "The gdb.TargetConnection for this inferior.", NULL },
> @@ -854,6 +1012,8 @@ static gdb_PyGetSetDef inferior_object_getset[] =
>    { "was_attached", infpy_get_was_attached, NULL,
>      "True if the inferior was created using 'attach'.", NULL },
>    { "progspace", infpy_get_progspace, NULL, "Program space of this inferior" },
> +  { "main_name", infpy_get_main_name, nullptr,
> +    "Name of 'main' function, if known.", nullptr },
>    { NULL }
>  };
>  
> @@ -889,6 +1049,15 @@ Return thread object corresponding to thread handle." },
>    { "architecture", (PyCFunction) infpy_architecture, METH_NOARGS,
>      "architecture () -> gdb.Architecture\n\
>  Return architecture of this inferior." },
> +  { "clear_env", (PyCFunction) infpy_clear_env, METH_NOARGS,
> +    "clear_env () -> None\n\
> +Clear environment of this inferior." },
> +  { "set_env", (PyCFunction) infpy_set_env, METH_VARARGS | METH_KEYWORDS,
> +    "set_env (name, value) -> None\n\
> +Set an environment variable of this inferior." },
> +  { "unset_env", (PyCFunction) infpy_unset_env, METH_VARARGS | METH_KEYWORDS,
> +    "unset_env (name) -> None\n\
> +Unset an environment of this inferior." },
>    { NULL }
>  };
>  
> diff --git a/gdb/testsuite/gdb.ada/py_range.exp b/gdb/testsuite/gdb.ada/py_range.exp
> index 2972db21827..833493bad95 100644
> --- a/gdb/testsuite/gdb.ada/py_range.exp
> +++ b/gdb/testsuite/gdb.ada/py_range.exp
> @@ -42,3 +42,7 @@ gdb_test "python print(gdb.parse_and_eval('si').type)" \
>      "foo\\.small_integer" "print type"
>  gdb_test "python print(gdb.parse_and_eval('si').type.name)" \
>      "foo\\.small_integer" "print type name"
> +
> +gdb_test "python print(gdb.selected_inferior().main_name)" \
> +    "_ada_foo" \
> +    "print main name"
> diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
> index 424050a6166..58deece5d5f 100644
> --- a/gdb/testsuite/gdb.python/py-inferior.exp
> +++ b/gdb/testsuite/gdb.python/py-inferior.exp
> @@ -342,3 +342,39 @@ with_test_prefix "architecture" {
>  	"True" \
>  	"inferior architecture matches frame architecture"
>  }
> +
> +gdb_test "python print(gdb.selected_inferior().main_name)" \
> +    "main" \
> +    "print main name"
> +
> +gdb_test_no_output "set args x y z"
> +gdb_test "python print(gdb.selected_inferior().arguments)" \
> +    "x y z" \
> +    "print arguments"
> +
> +gdb_test_no_output "python gdb.selected_inferior().arguments = 'a b c'" \
> +    "set arguments from string"
> +gdb_test "show args" \
> +    [string_to_regexp "Argument list to give program being debugged when it is started is \"a b c\"."] \
> +    "show args from string"
> +
> +gdb_test_no_output "python gdb.selected_inferior().arguments = \['a', 'b c'\]" \
> +    "set arguments from list"
> +gdb_test "show args" \
> +    [string_to_regexp "Argument list to give program being debugged when it is started is \"a b\\ c\"."] \
> +    "show args from list"
> +
> +gdb_test_no_output "python gdb.selected_inferior().clear_env()" \
> +    "clear environment"
> +gdb_test_no_output "show environment"
> +
> +gdb_test_no_output "python gdb.selected_inferior().set_env('DEI', 'value')" \
> +    "set environment variable"
> +gdb_test "show environment" \
> +    "DEI=value" \
> +    "examine environment variable"
> +
> +gdb_test_no_output "python gdb.selected_inferior().unset_env('DEI')" \
> +    "unset environment variable"
> +gdb_test_no_output "show environment" \
> +    "environment is empty again"
>
> -- 
> 2.40.0

[PATCH v2 2/2] Add "args" and "env" parameters to DAP launch request

[Tom Tromey]

This patch augments the DAP launch request with some optional new
parameters that let the client control the command-line arguments and
the environment of the inferior.

Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
---
 gdb/doc/gdb.texinfo                | 13 +++++-
 gdb/python/lib/gdb/dap/launch.py   | 20 ++++++++-
 gdb/testsuite/gdb.dap/args-env.c   | 28 ++++++++++++
 gdb/testsuite/gdb.dap/args-env.exp | 90 ++++++++++++++++++++++++++++++++++++++
 gdb/testsuite/lib/dap-support.exp  | 39 +++++++++++++----
 5 files changed, 178 insertions(+), 12 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 531147f6e6b..9570f12fa92 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -38998,10 +38998,21 @@ Generally, @value{GDBN} implements the Debugger Adapter Protocol as
 written.  However, in some cases, extensions are either needed or even
 expected.
 
-@value{GDBN} defines a parameter that can be passed to the
+@value{GDBN} defines some parameters that can be passed to the
 @code{launch} request:
 
 @table @code
+@item args
+If provided, this should be an array of strings.  These strings are
+provided as command-line arguments to the inferior, as if by
+@code{set args}.  @xref{Arguments}.
+
+@item env
+If provided, this should be an object.  Each key of the object will be
+used as the name of an environment variable; each value must be a
+string and will be the value of that variable.  The environment of the
+inferior will be set to exactly as passed in.  @xref{Environment}.
+
 @item program
 If provided, this is a string that specifies the program to use.  This
 corresponds to the @code{file} command.  @xref{Files}.
diff --git a/gdb/python/lib/gdb/dap/launch.py b/gdb/python/lib/gdb/dap/launch.py
index b4102cc28cc..21499a339e1 100644
--- a/gdb/python/lib/gdb/dap/launch.py
+++ b/gdb/python/lib/gdb/dap/launch.py
@@ -13,20 +13,36 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import gdb
 from .events import ExecutionInvoker
 from .server import request, capability
-from .startup import send_gdb
+from .startup import send_gdb, in_gdb_thread
 
 
 _program = None
 
 
+@in_gdb_thread
+def _set_args_env(args, env):
+    inf = gdb.selected_inferior()
+    inf.arguments = args
+    if env is not None:
+        inf.clear_env()
+        for name, value in env.items():
+            inf.set_env(name, value)
+
+
+# Any parameters here are necessarily extensions -- DAP requires this
+# from implementations.  Any additions or changes here should be
+# documented in the gdb manual.
 @request("launch")
-def launch(*, program=None, **args):
+def launch(*, program=None, args=[], env=None, **extra):
     if program is not None:
         global _program
         _program = program
         send_gdb(f"file {_program}")
+    if len(args) > 0 or env is not None:
+        send_gdb(lambda: _set_args_env(args, env))
 
 
 @capability("supportsConfigurationDoneRequest")
diff --git a/gdb/testsuite/gdb.dap/args-env.c b/gdb/testsuite/gdb.dap/args-env.c
new file mode 100644
index 00000000000..bc7f1d4b38e
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/args-env.c
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2023 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>
+#include <stdlib.h>
+
+int
+main (int argc, char *argv[])
+{
+  const char *value = getenv ("DEI");
+  const char *no_value = getenv ("NOSUCHVARIABLE");
+
+  return 0; /* BREAK */
+}
diff --git a/gdb/testsuite/gdb.dap/args-env.exp b/gdb/testsuite/gdb.dap/args-env.exp
new file mode 100644
index 00000000000..96fbb28d9ce
--- /dev/null
+++ b/gdb/testsuite/gdb.dap/args-env.exp
@@ -0,0 +1,90 @@
+# Copyright 2023 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/>.
+
+# Test environment variables and command line arguments via DAP.
+
+require allow_dap_tests !use_gdb_stub
+
+load_lib dap-support.exp
+
+standard_testfile
+
+if {[build_executable ${testfile}.exp $testfile] == -1} {
+    return
+}
+
+if {[dap_launch $testfile {a "b c"} {{DEI something}}] == ""} {
+    return
+}
+
+set line [gdb_get_line_number "BREAK"]
+set obj [dap_check_request_and_response "set breakpoint by line number" \
+	     setBreakpoints \
+	     [format {o source [o path [%s]] breakpoints [a [o line [i %d]]]} \
+		  [list s $srcfile] $line]]
+set line_bpno [dap_get_breakpoint_number $obj]
+
+dap_check_request_and_response "start inferior" configurationDone
+dap_wait_for_event_and_check "inferior started" thread "body reason" started
+
+dap_wait_for_event_and_check "stopped at line breakpoint" stopped \
+    "body reason" breakpoint \
+    "body hitBreakpointIds" $line_bpno
+
+set bt [lindex [dap_check_request_and_response "backtrace" stackTrace \
+		    {o threadId [i 1]}] \
+	    0]
+set frame_id [dict get [lindex [dict get $bt body stackFrames] 0] id]
+
+set obj [dap_check_request_and_response \
+	     "evaluate argc in function" \
+	     evaluate [format {o expression [s argc] frameId [i %s]} \
+			   $frame_id]]
+dap_match_values "argc in function" [lindex $obj 0] \
+    "body result" 3
+
+set obj [dap_check_request_and_response \
+	     "evaluate first argument in function" \
+	     evaluate [format {o expression [s {argv[1]}] frameId [i %s]} \
+			   $frame_id]]
+set val [dict get [lindex $obj 0] body result]
+# This ends up with some extra quoting.
+gdb_assert {[string first "\\\"a\\\"" $val] != -1} \
+    "first argument in function"
+
+set obj [dap_check_request_and_response \
+	     "evaluate second argument in function" \
+	     evaluate [format {o expression [s {argv[2]}] frameId [i %s]} \
+			   $frame_id]]
+set val [dict get [lindex $obj 0] body result]
+# This ends up with some extra quoting.
+gdb_assert {[string first "\\\"b c\\\"" $val] != -1} \
+    "second argument in function"
+
+set obj [dap_check_request_and_response "evaluate value in function" \
+	     evaluate [format {o expression [s value] frameId [i %s]} \
+			   $frame_id]]
+set val [dict get [lindex $obj 0] body result]
+# This ends up with some extra quoting.
+gdb_assert {[string first "\\\"something\\\"" $val] != -1} \
+    "value in function"
+
+set obj [dap_check_request_and_response "evaluate no_value in function" \
+	     evaluate [format {o expression [s no_value] frameId [i %s]} \
+			   $frame_id]]
+dap_match_values "no_value in function" [lindex $obj 0] \
+    "body result" 0
+
+dap_shutdown
diff --git a/gdb/testsuite/lib/dap-support.exp b/gdb/testsuite/lib/dap-support.exp
index 6bb9b6e6377..ead295bdbfe 100644
--- a/gdb/testsuite/lib/dap-support.exp
+++ b/gdb/testsuite/lib/dap-support.exp
@@ -236,17 +236,38 @@ proc _dap_initialize {name} {
 # Start gdb, send a DAP initialize request, and then a launch request
 # specifying FILE as the program to use for the inferior.  Returns the
 # empty string on failure, or the response object from the launch
-# request.  After this is called, gdb will be ready to accept
-# breakpoint requests.  NAME is used as the test name.  It has a
-# reasonable default but can be overridden in case a test needs to
-# launch gdb more than once.
-proc dap_launch {file {name startup}} {
-    if {[_dap_initialize "$name - initialize"] == ""} {
+# request.  If specified, ARGS is a list of command-line arguments,
+# and ENV is a list of pairs of the form {VAR VALUE} that is used to
+# populate the inferior's environment.  After this is called, gdb will
+# be ready to accept breakpoint requests.
+proc dap_launch {file {args {}} {env {}}} {
+    if {[_dap_initialize "startup - initialize"] == ""} {
 	return ""
     }
-    return [dap_check_request_and_response "$name - launch" launch \
-		[format {o program [%s]} \
-		     [list s [standard_output_file $file]]]]
+    set params "o program"
+    append params " [format {[%s]} [list s [standard_output_file $file]]]"
+
+    if {[llength $args] > 0} {
+	append params " args"
+	set arglist ""
+	foreach arg $args {
+	    append arglist " \[s [list $arg]\]"
+	}
+	append params " \[a $arglist\]"
+    }
+
+    if {[llength $env] > 0} {
+	append params " env"
+	set envlist ""
+	foreach pair $env {
+	    lassign $pair var value
+	    append envlist " $var"
+	    append envlist " [format {[%s]} [list s $value]]"
+	}
+	append params " \[o $envlist\]"
+    }
+
+    return [dap_check_request_and_response "startup - launch" launch $params]
 }
 
 # Cleanly shut down gdb.  NAME is used as the test name.

-- 
2.40.0

Re: [PATCH v2 0/2] Add more DAP launch parameters

[Tom Tromey]

>>>>> "Tom" == Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> This series adds some more Python attributes (and methods), and then
Tom> uses these to implement some new launch parameters for DAP.

Tom> Inferior.main_name is added but not used.  I plan to use this to
Tom> implement a "stop at main" launch parameter, after we work out a few
Tom> details.  Meanwhile it seemed harmless and potentially useful.

I'm checking this in.

Tom