* config/rx/rx.c (struct decl_chain): New local structure.

	(warned_decls): New local variable.  Contains a stack of decls for
	which warnings have been issued.
	(add_warned_decl): Adds a decl to the stack.
	(already_warned): Returns true if a given decl is on the stack.
	(rx_set_current_function): Issue a warning if multiple fast
	interrupt handlers are defined.
	* config/rx/rx.opt (mwarn-multiple-fast-interrupts): New option.
	* doc/invoke.texi: Document the option.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@192041 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 59 insertions, 0 deletions

diff --git a/gcc/config/rx/rx.c b/gcc/config/rx/rx.c
index 43676d1251c..5d31eac9738 100644
--- a/gcc/config/rx/rx.c
+++ b/gcc/config/rx/rx.c
@@ -1256,6 +1256,41 @@ rx_conditional_register_usage (void)
     }
 }
 
+struct decl_chain
+{
+  tree fndecl;
+  struct decl_chain * next;
+};
+
+/* Stack of decls for which we have issued warnings.  */
+static struct decl_chain * warned_decls = NULL;
+
+static void
+add_warned_decl (tree fndecl)
+{
+  struct decl_chain * warned = (struct decl_chain *) xmalloc (sizeof * warned);
+
+  warned->fndecl = fndecl;
+  warned->next = warned_decls;
+  warned_decls = warned;
+}
+
+/* Returns TRUE if FNDECL is on our list of warned about decls.  */
+
+static bool
+already_warned (tree fndecl)
+{
+  struct decl_chain * warned;
+
+  for (warned = warned_decls;
+       warned != NULL;
+       warned = warned->next)
+    if (warned->fndecl == fndecl)
+      return true;
+
+  return false;
+}
+
 /* Perform any actions necessary before starting to compile FNDECL.
    For the RX we use this to make sure that we have the correct
    set of register masks selected.  If FNDECL is NULL then we are
@@ -1288,6 +1323,24 @@ rx_set_current_function (tree fndecl)
       target_reinit ();
     }
 
+  if (current_is_fast_interrupt && rx_warn_multiple_fast_interrupts)
+    {
+      /* We do not warn about the first fast interrupt routine that
+	 we see.  Instead we just push it onto the stack.  */
+      if (warned_decls == NULL)
+	add_warned_decl (fndecl);
+
+      /* Otherwise if this fast interrupt is one for which we have
+	 not already issued a warning, generate one and then push
+	 it onto the stack as well.  */
+      else if (! already_warned (fndecl))
+	{
+	  warning (0, "multiple fast interrupt routines seen: %qE and %qE",
+		   fndecl, warned_decls->fndecl);
+	  add_warned_decl (fndecl);
+	}
+    }
+
   rx_previous_fndecl = fndecl;
 }
 
diff --git a/gcc/config/rx/rx.opt b/gcc/config/rx/rx.opt
index 76c2f61c79b..f0a57b1fae1 100644
--- a/gcc/config/rx/rx.opt
+++ b/gcc/config/rx/rx.opt
@@ -118,3 +118,9 @@ Specifies whether interrupt functions should save and restore the accumulator re
 mpid
 Target Mask(PID)
 Enables Position-Independent-Data (PID) mode.
+
+;---------------------------------------------------
+
+mwarn-multiple-fast-interrupts
+Target Report Var(rx_warn_multiple_fast_interrupts) Init(1) Warning
+Warn when multiple, different, fast interrupt handlers are in the compilation unit.