Add support for condition in Ada exception catchpoint commands

Previously, conditions could be associated to Ada exception catchpoints,
but not while creating the exception catchpoint:

    (gdb) catch exception first_exception if except_counter = 5
    Junk at end of expression

This patch improves the parsing of the command arguments to allow
an "if CONDITION" at the end.  All Ada exception catchpoint commands
have been enhanced to support this.

gdb/ChangeLog:

        * ada-lang.c (catch_ada_exception_command_split): Add new
        argument cond_string.  Add support for condition at end of
        "catch exception" commands.
        (ada_decode_exception_location): Add new argument cond_string.
        Update call to catch_ada_exception_command_split.
        (create_ada_exception_catchpoint): Add new argument cond_string.
        Set the breakpoint condition if needed.
        (catch_ada_exception_command): Update call to
        ada_decode_exception_location.
        (ada_decode_assert_location): Add function documentation.
        Add support for condition at end of "catch assert" command.
        (catch_assert_command): Update calls to ada_decode_assert_location
        and create_ada_exception_catchpoint.

1 files changed, 77 insertions, 13 deletions

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 107df93..216f703 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -11564,23 +11564,52 @@ ada_get_next_arg (char **argsp)
 /* Split the arguments specified in a "catch exception" command.  
    Set EX to the appropriate catchpoint type.
    Set EXCEP_STRING to the name of the specific exception if
-   specified by the user.  */
+   specified by the user.
+   If a condition is found at the end of the arguments, the condition
+   expression is stored in COND_STRING (memory must be deallocated
+   after use).  Otherwise COND_STRING is set to NULL.  */
 
 static void
 catch_ada_exception_command_split (char *args,
                                    enum exception_catchpoint_kind *ex,
-                                   char **excep_string)
+				   char **excep_string,
+				   char **cond_string)
 {
   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
   char *exception_name;
+  char *cond = NULL;
 
   exception_name = ada_get_next_arg (&args);
+  if (exception_name != NULL && strcmp (exception_name, "if") == 0)
+    {
+      /* This is not an exception name; this is the start of a condition
+	 expression for a catchpoint on all exceptions.  So, "un-get"
+	 this token, and set exception_name to NULL.  */
+      xfree (exception_name);
+      exception_name = NULL;
+      args -= 2;
+    }
   make_cleanup (xfree, exception_name);
 
-  /* Check that we do not have any more arguments.  Anything else
-     is unexpected.  */
+  /* Check to see if we have a condition.  */
 
   args = skip_spaces (args);
+  if (strncmp (args, "if", 2) == 0
+      && (isspace (args[2]) || args[2] == '\0'))
+    {
+      args += 2;
+      args = skip_spaces (args);
+
+      if (args[0] == '\0')
+        error (_("Condition missing after `if' keyword"));
+      cond = xstrdup (args);
+      make_cleanup (xfree, cond);
+
+      args += strlen (args);
+    }
+
+  /* Check that we do not have any more arguments.  Anything else
+     is unexpected.  */
 
   if (args[0] != '\0')
     error (_("Junk at end of expression"));
@@ -11605,6 +11634,7 @@ catch_ada_exception_command_split (char *args,
       *ex = ex_catch_exception;
       *excep_string = exception_name;
     }
+  *cond_string = cond;
 }
 
 /* Return the name of the symbol on which we should break in order to
@@ -11748,17 +11778,22 @@ ada_exception_sal (enum exception_catchpoint_kind ex, char *excep_string,
    If the user asked the catchpoint to catch only a specific
    exception, then save the exception name in ADDR_STRING.
 
+   If the user provided a condition, then set COND_STRING to
+   that condition expression (the memory must be deallocated
+   after use).  Otherwise, set COND_STRING to NULL.
+
    See ada_exception_sal for a description of all the remaining
    function arguments of this function.  */
 
 static struct symtab_and_line
 ada_decode_exception_location (char *args, char **addr_string,
                                char **excep_string,
+			       char **cond_string,
                                const struct breakpoint_ops **ops)
 {
   enum exception_catchpoint_kind ex;
 
-  catch_ada_exception_command_split (args, &ex, excep_string);
+  catch_ada_exception_command_split (args, &ex, excep_string, cond_string);
   return ada_exception_sal (ex, *excep_string, addr_string, ops);
 }
 
@@ -11769,6 +11804,7 @@ create_ada_exception_catchpoint (struct gdbarch *gdbarch,
 				 struct symtab_and_line sal,
 				 char *addr_string,
 				 char *excep_string,
+				 char *cond_string,
 				 const struct breakpoint_ops *ops,
 				 int tempflag,
 				 int from_tty)
@@ -11780,6 +11816,8 @@ create_ada_exception_catchpoint (struct gdbarch *gdbarch,
 				 ops, tempflag, from_tty);
   c->excep_string = excep_string;
   create_excep_cond_exprs (c);
+  if (cond_string != NULL)
+    set_breakpoint_condition (&c->base, cond_string, from_tty);
   install_breakpoint (0, &c->base, 1);
 }
 
@@ -11794,30 +11832,54 @@ catch_ada_exception_command (char *arg, int from_tty,
   struct symtab_and_line sal;
   char *addr_string = NULL;
   char *excep_string = NULL;
+  char *cond_string = NULL;
   const struct breakpoint_ops *ops = NULL;
 
   tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
 
   if (!arg)
     arg = "";
-  sal = ada_decode_exception_location (arg, &addr_string, &excep_string, &ops);
+  sal = ada_decode_exception_location (arg, &addr_string, &excep_string,
+				       &cond_string, &ops);
   create_ada_exception_catchpoint (gdbarch, sal, addr_string,
-				   excep_string, ops, tempflag, from_tty);
+				   excep_string, cond_string, ops,
+				   tempflag, from_tty);
 }
 
+/* Assuming that ARGS contains the arguments of a "catch assert"
+   command, parse those arguments and return a symtab_and_line object
+   for a failed assertion catchpoint.
+
+   Set ADDR_STRING to the name of the function where the real
+   breakpoint that implements the catchpoint is set.
+
+   If ARGS contains a condition, set COND_STRING to that condition
+   (the memory needs to be deallocated after use).  Otherwise, set
+   COND_STRING to NULL.  */
+
 static struct symtab_and_line
 ada_decode_assert_location (char *args, char **addr_string,
+			    char **cond_string,
                             const struct breakpoint_ops **ops)
 {
-  /* Check that no argument where provided at the end of the command.  */
+  args = skip_spaces (args);
 
-  if (args != NULL)
+  /* Check whether a condition was provided.  */
+  if (strncmp (args, "if", 2) == 0
+      && (isspace (args[2]) || args[2] == '\0'))
     {
+      args += 2;
       args = skip_spaces (args);
-      if (*args != '\0')
-        error (_("Junk at end of arguments."));
+      if (args[0] == '\0')
+        error (_("condition missing after `if' keyword"));
+      *cond_string = xstrdup (args);
     }
 
+  /* Otherwise, there should be no other argument at the end of
+     the command.  */
+  else if (args[0] != '\0')
+    error (_("Junk at end of arguments."));
+
   return ada_exception_sal (ex_catch_assert, NULL, addr_string, ops);
 }
 
@@ -11831,15 +11893,17 @@ catch_assert_command (char *arg, int from_tty,
   int tempflag;
   struct symtab_and_line sal;
   char *addr_string = NULL;
+  char *cond_string = NULL;
   const struct breakpoint_ops *ops = NULL;
 
   tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
 
   if (!arg)
     arg = "";
-  sal = ada_decode_assert_location (arg, &addr_string, &ops);
+  sal = ada_decode_assert_location (arg, &addr_string, &cond_string, &ops);
   create_ada_exception_catchpoint (gdbarch, sal, addr_string,
-				   NULL, ops, tempflag, from_tty);
+				   NULL, cond_string, ops, tempflag,
+				   from_tty);
 }
                                 /* Operators */
 /* Information about operators given special treatment in functions