Don't memset non-POD types: struct bp_location

struct bp_location is not a POD, so we shouldn't be using memset to
initialize it.

Caught like this:

  src/gdb/breakpoint.c: In function ‘bp_location** get_first_locp_gte_addr(CORE_ADDR)’:
  src/gdb/breakpoint.c:950:53: error: use of deleted function ‘void* memset(T*, int, size_t) [with T = bp_location; <template-parameter-1-2> = void; size_t = long unsigned int]’
     memset (&dummy_loc, 0, sizeof (struct bp_location));
						       ^
  In file included from src/gdb/defs.h:28:0,
		   from src/gdb/breakpoint.c:20:
  src/gdb/common/common-defs.h:126:7: note: declared here
   void *memset (T *s, int c, size_t n) = delete;
	 ^

gdb/ChangeLog:
2017-04-25  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (ada_catchpoint_location): Now a "class".  Remove
	"base" field and inherit from "bp_location" instead.  Add
	non-default ctor.
	(allocate_location_exception): Use new non-default ctor.
	* breakpoint.c (get_first_locp_gte_addr): Remove memset call.
	(init_bp_location): Convert to ...
	(bp_location::bp_location): ... this new ctor, and remove memset
	call.
	(base_breakpoint_allocate_location): Use the new non-default ctor.
	* breakpoint.h (bp_location): Now a class.  Declare default and
	non-default ctors.  In-class initialize all members.
	(init_bp_location): Remove declaration.

1 files changed, 7 insertions, 12 deletions

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 2e5643b..58c8a2e 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -12224,14 +12224,14 @@ static char *ada_exception_catchpoint_cond_string (const char *excep_string);
    when symbols change.  */
 
 /* An instance of this type is used to represent an Ada catchpoint
-   breakpoint location.  It includes a "struct bp_location" as a kind
-   of base class; users downcast to "struct bp_location *" when
-   needed.  */
+   breakpoint location.  */
 
-struct ada_catchpoint_location
+class ada_catchpoint_location : public bp_location
 {
-  /* The base class.  */
-  struct bp_location base;
+public:
+  ada_catchpoint_location (const bp_location_ops *ops, breakpoint *owner)
+    : bp_location (ops, owner)
+  {}
 
   /* The condition that checks whether the exception that was raised
      is the specific exception the user specified on catchpoint
@@ -12347,12 +12347,7 @@ static struct bp_location *
 allocate_location_exception (enum ada_exception_catchpoint_kind ex,
 			     struct breakpoint *self)
 {
-  struct ada_catchpoint_location *loc;
-
-  loc = new ada_catchpoint_location ();
-  init_bp_location (&loc->base, &ada_catchpoint_location_ops, self);
-  loc->excep_cond_expr = NULL;
-  return &loc->base;
+  return new ada_catchpoint_location (&ada_catchpoint_location_ops, self);
 }
 
 /* Implement the RE_SET method in the breakpoint_ops structure for all