[v2] guile: stop procedures on invalid breakpoints

Message ID &3who0-hc2sl7.6ynkv0/vea0fv3jcc&dmgggr7u3vzuqjsj5m5d@mail.bob131.so
State Superseded
Headers show
Series
  • [v2] guile: stop procedures on invalid breakpoints
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Commit Message

Simon Marchi via Gdb-patches June 9, 2021, 1:53 p.m.
Stop procedures on <gdb:breakpoint> objects are independent of the
breakpoints in GDB core: the only reference made to the GDB breakpoint
pointer in either of `breakpoint-stop' or `set-breakpoint-stop!' is in
the latter checking to ensure that there hasn't already been a stop
condition attached from elsewhere. This check is not applicable to
not-yet-registered <gdb:breakpoint> objects allocated from Scheme.

This commit changes the above-mentioned procedures to accept invalid
<gdb:breakpoint> objects originating from Scheme; this allows the
decoupling of the creation of a specific breakpoint object from its
registration (as well as making the interface less restrictive than it
needs to be).

gdb/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* guile/scm-breakpoint.c
	(bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe): Add
	helper function.
	(gdbscm_breakpoint_stop): Use
	bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe.
	(gdbscm_set_breakpoint_stop_x): Likewise.  Check that bp is
	non-NULL before doing condition string tests.

gdb/doc/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* guile.texi (Breakpoints In Guile): Add note that
	breakpoint-stop and set-breakpoint-stop! may be used on
	invalid <gdb:breakpoint> objects if they originated from
	Scheme.

gdb/testsuite/ChangeLog:

2021-06-09  George Barrett  <bob@bob131.so>

	* gdb.guile/scm-breakpoint.exp (test_bkpt_eval_funcs): Add
	tests for stop procedure manipulation on invalid
	<gdb:breakpoint> objects originating from Scheme.
	Add tests for stop procedure manipulation on valid and invalid
	<gdb:breakpoint> objects originating from GDB core.
---
 gdb/doc/guile.texi                         | 10 ++++
 gdb/guile/scm-breakpoint.c                 | 68 +++++++++++++++-------
 gdb/testsuite/gdb.guile/scm-breakpoint.exp | 37 +++++++++++-
 3 files changed, 92 insertions(+), 23 deletions(-)

-- 
2.31.1

Comments

Simon Marchi via Gdb-patches June 12, 2021, 10:08 a.m. | #1
> Date: Wed, 09 Jun 2021 23:53:48 +1000

> From: George Barrett via Gdb-patches <gdb-patches@sourceware.org>

> Cc: George Barrett <bob@bob131.so>

> 

> gdb/ChangeLog:

> 

> 2021-06-09  George Barrett  <bob@bob131.so>

> 

> 	* guile/scm-breakpoint.c

> 	(bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe): Add

> 	helper function.

> 	(gdbscm_breakpoint_stop): Use

> 	bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe.

> 	(gdbscm_set_breakpoint_stop_x): Likewise.  Check that bp is

> 	non-NULL before doing condition string tests.

> 

> gdb/doc/ChangeLog:

> 

> 2021-06-09  George Barrett  <bob@bob131.so>

> 

> 	* guile.texi (Breakpoints In Guile): Add note that

> 	breakpoint-stop and set-breakpoint-stop! may be used on

> 	invalid <gdb:breakpoint> objects if they originated from

> 	Scheme.

> 

> gdb/testsuite/ChangeLog:

> 

> 2021-06-09  George Barrett  <bob@bob131.so>

> 

> 	* gdb.guile/scm-breakpoint.exp (test_bkpt_eval_funcs): Add

> 	tests for stop procedure manipulation on invalid

> 	<gdb:breakpoint> objects originating from Scheme.

> 	Add tests for stop procedure manipulation on valid and invalid

> 	<gdb:breakpoint> objects originating from GDB core.


Thanks, the documentation part is okay.
Simon Marchi via Gdb-patches June 17, 2021, 2:54 p.m. | #2
> diff --git a/gdb/guile/scm-breakpoint.c b/gdb/guile/scm-breakpoint.c

> index 4ff197e48a4..3c741d712b7 100644

> --- a/gdb/guile/scm-breakpoint.c

> +++ b/gdb/guile/scm-breakpoint.c

> @@ -326,6 +326,26 @@ bpscm_get_valid_breakpoint_smob_arg_unsafe (SCM self, int arg_pos,

>  

>    return bp_smob;

>  }

> +

> +/* Returns the breakpoint smob in SELF, verifying it's either valid or

> +   originates from Scheme.

> +   Throws an exception if SELF is not a <gdb:breakpoint> object,

> +   or is invalid and not allocated from Scheme.  */

> +

> +static breakpoint_smob *

> +bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (SCM self, int arg_pos,

> +						   const char *func_name)

> +{

> +  breakpoint_smob *bp_smob

> +    = bpscm_get_breakpoint_smob_arg_unsafe (self, arg_pos, func_name);

> +

> +  if (!bpscm_is_valid (bp_smob) && !bp_smob->is_scheme_bkpt)

> +    gdbscm_invalid_object_error (func_name, arg_pos, self,

> +				 _("<gdb:breakpoint>"));

> +

> +

> +  return bp_smob;


Remove extra empty line above.

> +}

>  

>  /* Breakpoint methods.  */

>  

> @@ -914,7 +934,8 @@ static SCM

>  gdbscm_breakpoint_stop (SCM self)

>  {

>    breakpoint_smob *bp_smob

> -    = bpscm_get_valid_breakpoint_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);

> +    = bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (self, SCM_ARG1,

> +							 FUNC_NAME);

>  

>    return bp_smob->stop;

>  }

> @@ -926,33 +947,36 @@ static SCM

>  gdbscm_set_breakpoint_stop_x (SCM self, SCM newvalue)

>  {

>    breakpoint_smob *bp_smob

> -    = bpscm_get_valid_breakpoint_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);

> -  const struct extension_language_defn *extlang = NULL;

> +    = bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (self, SCM_ARG1,

> +							 FUNC_NAME);

>  

>    SCM_ASSERT_TYPE (gdbscm_is_procedure (newvalue)

>  		   || gdbscm_is_false (newvalue),

>  		   newvalue, SCM_ARG2, FUNC_NAME,

>  		   _("procedure or #f"));

>  

> -  if (bp_smob->bp->cond_string != NULL)

> -    extlang = get_ext_lang_defn (EXT_LANG_GDB);

> -  if (extlang == NULL)

> -    extlang = get_breakpoint_cond_ext_lang (bp_smob->bp, EXT_LANG_GUILE);

> -  if (extlang != NULL)

> -    {

> -      char *error_text

> -	= xstrprintf (_("Only one stop condition allowed.  There is"

> -			" currently a %s stop condition defined for"

> -			" this breakpoint."),

> -		      ext_lang_capitalized_name (extlang));

> -

> -      scm_dynwind_begin ((scm_t_dynwind_flags) 0);

> -      gdbscm_dynwind_xfree (error_text);

> -      gdbscm_out_of_range_error (FUNC_NAME, SCM_ARG1, self, error_text);

> -      /* The following line, while unnecessary, is present for completeness

> -	 sake.  */

> -      scm_dynwind_end ();

> -    }

> +  if (bp_smob->bp != nullptr) {

> +    const struct extension_language_defn *extlang = nullptr;

> +    if (bp_smob->bp->cond_string != nullptr)

> +      extlang = get_ext_lang_defn (EXT_LANG_GDB);

> +    if (extlang == nullptr)

> +      extlang = get_breakpoint_cond_ext_lang (bp_smob->bp, EXT_LANG_GUILE);

> +    if (extlang != nullptr)

> +      {

> +	char *error_text

> +	  = xstrprintf (_("Only one stop condition allowed.  There is"

> +			  " currently a %s stop condition defined for"

> +			  " this breakpoint."),

> +			ext_lang_capitalized_name (extlang));

> +

> +	scm_dynwind_begin ((scm_t_dynwind_flags) 0);

> +	gdbscm_dynwind_xfree (error_text);

> +	gdbscm_out_of_range_error (FUNC_NAME, SCM_ARG1, self, error_text);

> +	/* The following line, while unnecessary, is present for

> +	   completeness sake.  */

> +	scm_dynwind_end ();

> +      }

> +  }


Format the if above with the usual style:

  if (...)
    {
      ...
    }

The patch LGTM with those fixed.  Again, we will be able to merge it
once your copyright assignment is complete, just remind us then.

Simon

Patch

diff --git a/gdb/doc/guile.texi b/gdb/doc/guile.texi
index c7e43c8d63a..84590eb19bf 100644
--- a/gdb/doc/guile.texi
+++ b/gdb/doc/guile.texi
@@ -3182,6 +3182,11 @@  becomes unconditional.
 @deffn {Scheme Procedure} breakpoint-stop breakpoint
 Return the stop predicate of @var{breakpoint}.
 See @code{set-breakpoint-stop!} below in this section.
+
+If @var{breakpoint} was created using @code{make-breakpoint}, this
+procedure may be used even if @code{breakpoint-valid?} would return
+@code{#f}.  In that case it returns the stop procedure that will be used
+by @var{breakpoint} once the breakpoint has been registered.
 @end deffn
 
 @deffn {Scheme Procedure} set-breakpoint-stop! breakpoint procedure|#f
@@ -3215,6 +3220,11 @@  Example @code{stop} implementation:
 (register-breakpoint! bkpt)
 (set-breakpoint-stop! bkpt my-stop?)
 @end smallexample
+
+If @var{breakpoint} was created using @code{make-breakpoint}, this
+procedure may be used even if @code{breakpoint-valid?} would return
+@code{#f}.  In that case @var{procedure} will be the stop procedure for
+@var{breakpoint} when the breakpoint is registered.
 @end deffn
 
 @deffn {Scheme Procedure} breakpoint-commands breakpoint
diff --git a/gdb/guile/scm-breakpoint.c b/gdb/guile/scm-breakpoint.c
index 4ff197e48a4..3c741d712b7 100644
--- a/gdb/guile/scm-breakpoint.c
+++ b/gdb/guile/scm-breakpoint.c
@@ -326,6 +326,26 @@  bpscm_get_valid_breakpoint_smob_arg_unsafe (SCM self, int arg_pos,
 
   return bp_smob;
 }
+
+/* Returns the breakpoint smob in SELF, verifying it's either valid or
+   originates from Scheme.
+   Throws an exception if SELF is not a <gdb:breakpoint> object,
+   or is invalid and not allocated from Scheme.  */
+
+static breakpoint_smob *
+bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (SCM self, int arg_pos,
+						   const char *func_name)
+{
+  breakpoint_smob *bp_smob
+    = bpscm_get_breakpoint_smob_arg_unsafe (self, arg_pos, func_name);
+
+  if (!bpscm_is_valid (bp_smob) && !bp_smob->is_scheme_bkpt)
+    gdbscm_invalid_object_error (func_name, arg_pos, self,
+				 _("<gdb:breakpoint>"));
+
+
+  return bp_smob;
+}
 
 /* Breakpoint methods.  */
 
@@ -914,7 +934,8 @@  static SCM
 gdbscm_breakpoint_stop (SCM self)
 {
   breakpoint_smob *bp_smob
-    = bpscm_get_valid_breakpoint_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
+    = bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (self, SCM_ARG1,
+							 FUNC_NAME);
 
   return bp_smob->stop;
 }
@@ -926,33 +947,36 @@  static SCM
 gdbscm_set_breakpoint_stop_x (SCM self, SCM newvalue)
 {
   breakpoint_smob *bp_smob
-    = bpscm_get_valid_breakpoint_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
-  const struct extension_language_defn *extlang = NULL;
+    = bpscm_get_valid_or_scm_breakpoint_smob_arg_unsafe (self, SCM_ARG1,
+							 FUNC_NAME);
 
   SCM_ASSERT_TYPE (gdbscm_is_procedure (newvalue)
 		   || gdbscm_is_false (newvalue),
 		   newvalue, SCM_ARG2, FUNC_NAME,
 		   _("procedure or #f"));
 
-  if (bp_smob->bp->cond_string != NULL)
-    extlang = get_ext_lang_defn (EXT_LANG_GDB);
-  if (extlang == NULL)
-    extlang = get_breakpoint_cond_ext_lang (bp_smob->bp, EXT_LANG_GUILE);
-  if (extlang != NULL)
-    {
-      char *error_text
-	= xstrprintf (_("Only one stop condition allowed.  There is"
-			" currently a %s stop condition defined for"
-			" this breakpoint."),
-		      ext_lang_capitalized_name (extlang));
-
-      scm_dynwind_begin ((scm_t_dynwind_flags) 0);
-      gdbscm_dynwind_xfree (error_text);
-      gdbscm_out_of_range_error (FUNC_NAME, SCM_ARG1, self, error_text);
-      /* The following line, while unnecessary, is present for completeness
-	 sake.  */
-      scm_dynwind_end ();
-    }
+  if (bp_smob->bp != nullptr) {
+    const struct extension_language_defn *extlang = nullptr;
+    if (bp_smob->bp->cond_string != nullptr)
+      extlang = get_ext_lang_defn (EXT_LANG_GDB);
+    if (extlang == nullptr)
+      extlang = get_breakpoint_cond_ext_lang (bp_smob->bp, EXT_LANG_GUILE);
+    if (extlang != nullptr)
+      {
+	char *error_text
+	  = xstrprintf (_("Only one stop condition allowed.  There is"
+			  " currently a %s stop condition defined for"
+			  " this breakpoint."),
+			ext_lang_capitalized_name (extlang));
+
+	scm_dynwind_begin ((scm_t_dynwind_flags) 0);
+	gdbscm_dynwind_xfree (error_text);
+	gdbscm_out_of_range_error (FUNC_NAME, SCM_ARG1, self, error_text);
+	/* The following line, while unnecessary, is present for
+	   completeness sake.  */
+	scm_dynwind_end ();
+      }
+  }
 
   bp_smob->stop = newvalue;
 
diff --git a/gdb/testsuite/gdb.guile/scm-breakpoint.exp b/gdb/testsuite/gdb.guile/scm-breakpoint.exp
index 56058942e64..1739793465c 100644
--- a/gdb/testsuite/gdb.guile/scm-breakpoint.exp
+++ b/gdb/testsuite/gdb.guile/scm-breakpoint.exp
@@ -376,10 +376,45 @@  proc_with_prefix test_bkpt_eval_funcs { } {
 	"= 4" \
 	"check non firing same-location breakpoint eval function was also called at each stop 2"
 
+    # Check that stop funcs can be manipulated on invalid Scheme-created
+    # breakpoints.
+
+    delete_breakpoints
+    gdb_test "guile (print (breakpoint-valid? eval-bp1))" "= #f" \
+	"check Scheme-created breakpoint is invalid"
+    gdb_scm_test_silent_cmd "guile (set-breakpoint-stop! eval-bp1 (const 'test!))" \
+	"check setting stop procedure on invalid Scheme-created breakpoint"
+    gdb_test "guile (print ((breakpoint-stop eval-bp1)))" "= test!" \
+	"check stop procedure on invalid Scheme-created breakpoint was successfully set"
+
+    # Check that stop funcs can be manipulated on breakpoint wrappers.
+
+    gdb_breakpoint "main"
+    gdb_scm_test_silent_cmd "guile (define bp-wrapper (car (breakpoints)))" \
+	"get breakpoint wrapper"
+    gdb_test "guile (print (breakpoint-valid? bp-wrapper))" "= #t" \
+	"check breakpoint wrapper is valid"
+    gdb_scm_test_silent_cmd "guile (set-breakpoint-stop! bp-wrapper (const 'test!))" \
+	"check setting stop procedure on breakpoit wrapper"
+    gdb_test "guile (print ((breakpoint-stop bp-wrapper)))" "= test!" \
+	"check stop procedure on breakpoint wrapper was successfully set"
+
+    # Check that stop funcs cannot be manipulated on invalid breakpoint
+    # wrappers.
+
+    delete_breakpoints
+    gdb_test "guile (print (breakpoint-valid? bp-wrapper))" "= #f" \
+	"check breakpoint wrapper is invalid"
+    gdb_test "guile (set-breakpoint-stop! bp-wrapper (const 'test!))" \
+	"ERROR:.*Invalid object: <gdb:breakpoint>.*" \
+	"check stop procedure cannot be set on invalid breakpoint wrapper"
+    gdb_test "guile (breakpoint-stop bp-wrapper)" \
+	"ERROR:.*Invalid object: <gdb:breakpoint>.*" \
+	"check stop procedure cannot be retrieved from invalid breakpoint wrapper"
+
     # Check we cannot assign a condition to a breakpoint with a stop-func,
     # and cannot assign a stop-func to a breakpoint with a condition.
 
-    delete_breakpoints
     set cond_bp [gdb_get_line_number "Break at multiply."]
     gdb_scm_test_silent_cmd  "guile (define eval-bp1 (make-bp-eval \"$cond_bp\"))" \
 	"create eval-bp1 breakpoint 2"