[RFA 2/3] Return std::string from ada_exception_catchpoint_cond_string

[Tom Tromey <tom at tromey dot com>]

This changes ada_exception_catchpoint_cond_string to return a
std::string, allowing for the removal of a cleanup in
create_excep_cond_exprs.

ChangeLog
2018-05-03  Tom Tromey  <tom@tromey.com>

	* ada-lang.c (create_excep_cond_exprs): Update.
	(ada_exception_catchpoint_cond_string): Use std::string.
---
 gdb/ChangeLog  |  5 +++++
 gdb/ada-lang.c | 36 ++++++++++++++----------------------
 2 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index d086240459..1af09bc00e 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -12431,7 +12431,7 @@ ada_exception_name_addr (enum ada_exception_catchpoint_kind ex,
   return result;
 }
 
-static char *ada_exception_catchpoint_cond_string
+static std::string ada_exception_catchpoint_cond_string
   (const char *excep_string,
    enum ada_exception_catchpoint_kind ex);
 
@@ -12499,9 +12499,7 @@ static void
 create_excep_cond_exprs (struct ada_catchpoint *c,
                          enum ada_exception_catchpoint_kind ex)
 {
-  struct cleanup *old_chain;
   struct bp_location *bl;
-  char *cond_string;
 
   /* Nothing to do if there's no specific exception to catch.  */
   if (c->excep_string == NULL)
@@ -12513,8 +12511,8 @@ create_excep_cond_exprs (struct ada_catchpoint *c,
 
   /* Compute the condition expression in text form, from the specific
      expection we want to catch.  */
-  cond_string = ada_exception_catchpoint_cond_string (c->excep_string, ex);
-  old_chain = make_cleanup (xfree, cond_string);
+  std::string cond_string
+    = ada_exception_catchpoint_cond_string (c->excep_string, ex);
 
   /* Iterate over all the catchpoint's locations, and parse an
      expression for each.  */
@@ -12528,7 +12526,7 @@ create_excep_cond_exprs (struct ada_catchpoint *c,
 	{
 	  const char *s;
 
-	  s = cond_string;
+	  s = cond_string.c_str ();
 	  TRY
 	    {
 	      exp = parse_exp_1 (&s, bl->address,
@@ -12546,8 +12544,6 @@ create_excep_cond_exprs (struct ada_catchpoint *c,
 
       ada_loc->excep_cond_expr = std::move (exp);
     }
-
-  do_cleanups (old_chain);
 }
 
 /* ada_catchpoint destructor.  */
@@ -13248,29 +13244,25 @@ ada_exception_breakpoint_ops (enum ada_exception_catchpoint_kind ex)
    being raised with the exception that the user wants to catch.  This
    assumes that this condition is used when the inferior just triggered
    an exception catchpoint.
-   EX: the type of catchpoints used for catching Ada exceptions.
-   
-   The string returned is a newly allocated string that needs to be
-   deallocated later.  */
+   EX: the type of catchpoints used for catching Ada exceptions.  */
 
-static char *
+static std::string
 ada_exception_catchpoint_cond_string (const char *excep_string,
                                       enum ada_exception_catchpoint_kind ex)
 {
   int i;
   bool is_standard_exc = false;
-  const char *actual_exc_expr;
-  char *ref_exc_expr;
+  std::string result;
 
   if (ex == ada_catch_handlers)
     {
       /* For exception handlers catchpoints, the condition string does
          not use the same parameter as for the other exceptions.  */
-      actual_exc_expr = ("long_integer (GNAT_GCC_exception_Access"
-			 "(gcc_exception).all.occurrence.id)");
+      result = ("long_integer (GNAT_GCC_exception_Access"
+		"(gcc_exception).all.occurrence.id)");
     }
   else
-    actual_exc_expr = "long_integer (e)";
+    result = "long_integer (e)";
 
   /* The standard exceptions are a special case.  They are defined in
      runtime units that have been compiled without debugging info; if
@@ -13300,13 +13292,13 @@ ada_exception_catchpoint_cond_string (const char *excep_string,
 	}
     }
 
+  result += " = ";
+
   if (is_standard_exc)
-    ref_exc_expr = xstrprintf ("long_integer (&standard.%s)", excep_string);
+    string_appendf (result, "long_integer (&standard.%s)", excep_string);
   else
-    ref_exc_expr = xstrprintf ("long_integer (&%s)", excep_string);
+    string_appendf (result, "long_integer (&%s)", excep_string);
 
-  char *result =  xstrprintf ("%s = %s", actual_exc_expr, ref_exc_expr);
-  xfree (ref_exc_expr);
   return result;
 }
 
-- 
2.13.6