[PATCH 2/9] Move `compute_probe_arg' and `compile_probe_arg' to probe.c

["Jose E. Marchesi" <jose.marchesi@oracle.com>]

This patch moves the `compute_probe_arg' and `compile_probe_arg' functions
from stap-probe.c to probe.c.  The rationale is that it is reasonable to
assume that all backends will provide the `$_probe_argN' convenience
variables, and that the user must be placed on the PC of the probe when
requesting that information.  The value and type of the argument can still be
determined by the probe backend via the `pops->evaluate_probe_argument' and
`pops->compile_to_ax' handlers.

Note that a test in gdb.base/stap-probe.exp had to be adjusted because the "No
SystemTap probe at PC" messages are now "No probe at PC".

gdb:

2014-09-26  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* probe.c (compute_probe_arg): Function moved from the probe
	backends.
	(compile_probe_arg): Likewise.
	(probe_funcs): Likewise.

	* stap-probe.c (compute_probe_arg): Deleted.
	(compile_probe_arg): Likewise.
	(probe_funcs): Likewise.

gdb/testsuite:

2014-09-26  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* gdb.base/stap-probe.exp (stap_test): Remove "SystemTap" from
	expected message when trying to access $_probe_* convenience
	variables while not on a probe.
---
 gdb/ChangeLog                         |   11 ++++
 gdb/probe.c                           |  111 +++++++++++++++++++++++++++++++++
 gdb/stap-probe.c                      |  109 --------------------------------
 gdb/testsuite/ChangeLog               |    6 ++
 gdb/testsuite/gdb.base/stap-probe.exp |    2 +-
 5 files changed, 129 insertions(+), 110 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7cc4f00..5ec0d85 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2014-09-26  Jose E. Marchesi  <jose.marchesi@oracle.com>
+
+	* probe.c (compute_probe_arg): Function moved from the probe
+	backends.
+	(compile_probe_arg): Likewise.
+	(probe_funcs): Likewise.
+
+	* stap-probe.c (compute_probe_arg): Deleted.
+	(compile_probe_arg): Likewise.
+	(probe_funcs): Likewise.
+
 2014-09-25  Jose E. Marchesi  <jose.marchesi@oracle.com>
 
 	* probe.c (print_ui_out_not_applicables): New function.
diff --git a/gdb/probe.c b/gdb/probe.c
index 5458372..d218f00 100644
--- a/gdb/probe.c
+++ b/gdb/probe.c
@@ -31,6 +31,9 @@
 #include "gdb_regex.h"
 #include "frame.h"
 #include "arch-utils.h"
+#include "value.h"
+#include "ax.h"
+#include "ax-gdb.h"
 #include <ctype.h>
 
 typedef struct bound_probe bound_probe_s;
@@ -822,6 +825,87 @@ will show information about all types of probes."),
   return &info_probes_cmdlist;
 }
 
+\f
+
+/* This is called to compute the value of one of the $_probe_arg*
+   convenience variables.  */
+
+static struct value *
+compute_probe_arg (struct gdbarch *arch, struct internalvar *ivar,
+		   void *data)
+{
+  struct frame_info *frame = get_selected_frame (_("No frame selected"));
+  CORE_ADDR pc = get_frame_pc (frame);
+  int sel = (int) (uintptr_t) data;
+  struct bound_probe pc_probe;
+  const struct sym_probe_fns *pc_probe_fns;
+  unsigned n_args;
+
+  /* SEL == -1 means "_probe_argc".  */
+  gdb_assert (sel >= -1);
+
+  pc_probe = find_probe_by_pc (pc);
+  if (pc_probe.probe == NULL)
+    error (_("No probe at PC %s"), core_addr_to_string (pc));
+
+  n_args = get_probe_argument_count (pc_probe.probe, frame);
+  if (sel == -1)
+    return value_from_longest (builtin_type (arch)->builtin_int, n_args);
+
+  if (sel >= n_args)
+    error (_("Invalid probe argument %d -- probe has %u arguments available"),
+	   sel, n_args);
+
+  return evaluate_probe_argument (pc_probe.probe, sel, frame);
+}
+
+/* This is called to compile one of the $_probe_arg* convenience
+   variables into an agent expression.  */
+
+static void
+compile_probe_arg (struct internalvar *ivar, struct agent_expr *expr,
+		   struct axs_value *value, void *data)
+{
+  CORE_ADDR pc = expr->scope;
+  int sel = (int) (uintptr_t) data;
+  struct bound_probe pc_probe;
+  const struct sym_probe_fns *pc_probe_fns;
+  int n_args;
+  struct frame_info *frame = get_selected_frame (NULL);
+
+  /* SEL == -1 means "_probe_argc".  */
+  gdb_assert (sel >= -1);
+
+  pc_probe = find_probe_by_pc (pc);
+  if (pc_probe.probe == NULL)
+    error (_("No probe at PC %s"), core_addr_to_string (pc));
+
+  n_args = get_probe_argument_count (pc_probe.probe, frame);
+
+  if (sel == -1)
+    {
+      value->kind = axs_rvalue;
+      value->type = builtin_type (expr->gdbarch)->builtin_int;
+      ax_const_l (expr, n_args);
+      return;
+    }
+
+  gdb_assert (sel >= 0);
+  if (sel >= n_args)
+    error (_("Invalid probe argument %d -- probe has %d arguments available"),
+	   sel, n_args);
+
+  pc_probe.probe->pops->compile_to_ax (pc_probe.probe, expr, value, sel);
+}
+
+static const struct internalvar_funcs probe_funcs =
+{
+  compute_probe_arg,
+  compile_probe_arg,
+  NULL
+};
+
+
 VEC (probe_ops_cp) *all_probe_ops;
 
 void _initialize_probe (void);
@@ -831,6 +915,33 @@ _initialize_probe (void)
 {
   VEC_safe_push (probe_ops_cp, all_probe_ops, &probe_ops_any);
 
+  create_internalvar_type_lazy ("_probe_argc", &probe_funcs,
+				(void *) (uintptr_t) -1);
+  create_internalvar_type_lazy ("_probe_arg0", &probe_funcs,
+				(void *) (uintptr_t) 0);
+  create_internalvar_type_lazy ("_probe_arg1", &probe_funcs,
+				(void *) (uintptr_t) 1);
+  create_internalvar_type_lazy ("_probe_arg2", &probe_funcs,
+				(void *) (uintptr_t) 2);
+  create_internalvar_type_lazy ("_probe_arg3", &probe_funcs,
+				(void *) (uintptr_t) 3);
+  create_internalvar_type_lazy ("_probe_arg4", &probe_funcs,
+				(void *) (uintptr_t) 4);
+  create_internalvar_type_lazy ("_probe_arg5", &probe_funcs,
+				(void *) (uintptr_t) 5);
+  create_internalvar_type_lazy ("_probe_arg6", &probe_funcs,
+				(void *) (uintptr_t) 6);
+  create_internalvar_type_lazy ("_probe_arg7", &probe_funcs,
+				(void *) (uintptr_t) 7);
+  create_internalvar_type_lazy ("_probe_arg8", &probe_funcs,
+				(void *) (uintptr_t) 8);
+  create_internalvar_type_lazy ("_probe_arg9", &probe_funcs,
+				(void *) (uintptr_t) 9);
+  create_internalvar_type_lazy ("_probe_arg10", &probe_funcs,
+				(void *) (uintptr_t) 10);
+  create_internalvar_type_lazy ("_probe_arg11", &probe_funcs,
+				(void *) (uintptr_t) 11);
+
   add_cmd ("all", class_info, info_probes_command,
 	   _("\
 Show information about all type of probes."),
diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index 23202d7..17a73fc 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -1366,79 +1366,6 @@ stap_probe_destroy (struct probe *probe_generic)
 
 \f
 
-/* This is called to compute the value of one of the $_probe_arg*
-   convenience variables.  */
-
-static struct value *
-compute_probe_arg (struct gdbarch *arch, struct internalvar *ivar,
-		   void *data)
-{
-  struct frame_info *frame = get_selected_frame (_("No frame selected"));
-  CORE_ADDR pc = get_frame_pc (frame);
-  int sel = (int) (uintptr_t) data;
-  struct bound_probe pc_probe;
-  const struct sym_probe_fns *pc_probe_fns;
-  unsigned n_args;
-
-  /* SEL == -1 means "_probe_argc".  */
-  gdb_assert (sel >= -1);
-
-  pc_probe = find_probe_by_pc (pc);
-  if (pc_probe.probe == NULL)
-    error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc));
-
-  n_args = get_probe_argument_count (pc_probe.probe, frame);
-  if (sel == -1)
-    return value_from_longest (builtin_type (arch)->builtin_int, n_args);
-
-  if (sel >= n_args)
-    error (_("Invalid probe argument %d -- probe has %u arguments available"),
-	   sel, n_args);
-
-  return evaluate_probe_argument (pc_probe.probe, sel, frame);
-}
-
-/* This is called to compile one of the $_probe_arg* convenience
-   variables into an agent expression.  */
-
-static void
-compile_probe_arg (struct internalvar *ivar, struct agent_expr *expr,
-		   struct axs_value *value, void *data)
-{
-  CORE_ADDR pc = expr->scope;
-  int sel = (int) (uintptr_t) data;
-  struct bound_probe pc_probe;
-  const struct sym_probe_fns *pc_probe_fns;
-  int n_args;
-  struct frame_info *frame = get_selected_frame (NULL);
-
-  /* SEL == -1 means "_probe_argc".  */
-  gdb_assert (sel >= -1);
-
-  pc_probe = find_probe_by_pc (pc);
-  if (pc_probe.probe == NULL)
-    error (_("No SystemTap probe at PC %s"), core_addr_to_string (pc));
-
-  n_args = get_probe_argument_count (pc_probe.probe, frame);
-
-  if (sel == -1)
-    {
-      value->kind = axs_rvalue;
-      value->type = builtin_type (expr->gdbarch)->builtin_int;
-      ax_const_l (expr, n_args);
-      return;
-    }
-
-  gdb_assert (sel >= 0);
-  if (sel >= n_args)
-    error (_("Invalid probe argument %d -- probe has %d arguments available"),
-	   sel, n_args);
-
-  pc_probe.probe->pops->compile_to_ax (pc_probe.probe, expr, value, sel);
-}
-
-\f
-
 /* Set or clear a SystemTap semaphore.  ADDRESS is the semaphore's
    address.  SET is zero if the semaphore should be cleared, or one
    if it should be set.  This is a helper function for `stap_semaphore_down'
@@ -1515,15 +1442,6 @@ stap_clear_semaphore (struct probe *probe_generic, struct objfile *objfile,
   stap_modify_semaphore (addr, 0, gdbarch);
 }
 
-/* Implementation of `$_probe_arg*' set of variables.  */
-
-static const struct internalvar_funcs probe_funcs =
-{
-  compute_probe_arg,
-  compile_probe_arg,
-  NULL
-};
-
 /* Helper function that parses the information contained in a
    SystemTap's probe.  Basically, the information consists in:
 
@@ -1784,33 +1702,6 @@ _initialize_stap_probe (void)
 			     show_stapexpressiondebug,
 			     &setdebuglist, &showdebuglist);
 
-  create_internalvar_type_lazy ("_probe_argc", &probe_funcs,
-				(void *) (uintptr_t) -1);
-  create_internalvar_type_lazy ("_probe_arg0", &probe_funcs,
-				(void *) (uintptr_t) 0);
-  create_internalvar_type_lazy ("_probe_arg1", &probe_funcs,
-				(void *) (uintptr_t) 1);
-  create_internalvar_type_lazy ("_probe_arg2", &probe_funcs,
-				(void *) (uintptr_t) 2);
-  create_internalvar_type_lazy ("_probe_arg3", &probe_funcs,
-				(void *) (uintptr_t) 3);
-  create_internalvar_type_lazy ("_probe_arg4", &probe_funcs,
-				(void *) (uintptr_t) 4);
-  create_internalvar_type_lazy ("_probe_arg5", &probe_funcs,
-				(void *) (uintptr_t) 5);
-  create_internalvar_type_lazy ("_probe_arg6", &probe_funcs,
-				(void *) (uintptr_t) 6);
-  create_internalvar_type_lazy ("_probe_arg7", &probe_funcs,
-				(void *) (uintptr_t) 7);
-  create_internalvar_type_lazy ("_probe_arg8", &probe_funcs,
-				(void *) (uintptr_t) 8);
-  create_internalvar_type_lazy ("_probe_arg9", &probe_funcs,
-				(void *) (uintptr_t) 9);
-  create_internalvar_type_lazy ("_probe_arg10", &probe_funcs,
-				(void *) (uintptr_t) 10);
-  create_internalvar_type_lazy ("_probe_arg11", &probe_funcs,
-				(void *) (uintptr_t) 11);
-
   add_cmd ("stap", class_info, info_probes_stap_command,
 	   _("\
 Show information about SystemTap static probes.\n\
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 539a983..c93d7cf 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2014-09-26  Jose E. Marchesi  <jose.marchesi@oracle.com>
+
+	* gdb.base/stap-probe.exp (stap_test): Remove "SystemTap" from
+	expected message when trying to access $_probe_* convenience
+	variables while not on a probe.
+
 2014-09-22  Pedro Alves  <palves@redhat.com>
 
 	* gdb.threads/break-while-running.exp: New file.
diff --git a/gdb/testsuite/gdb.base/stap-probe.exp b/gdb/testsuite/gdb.base/stap-probe.exp
index 7710bc3..9f71d1d 100644
--- a/gdb/testsuite/gdb.base/stap-probe.exp
+++ b/gdb/testsuite/gdb.base/stap-probe.exp
@@ -30,7 +30,7 @@ proc stap_test {exec_name {arg ""}} {
 	return -1
     }
 
-    gdb_test "print \$_probe_argc" "No SystemTap probe at PC $hex" \
+    gdb_test "print \$_probe_argc" "No probe at PC $hex" \
 	"check argument not at probe point"
 
     gdb_test "info probes stap" \
-- 
1.7.10.4