gimple-low.c (lower_stmt): If the call is noreturn, remove a subsequent GOTO or RETUR...

	* gimple-low.c (lower_stmt) <GIMPLE_CALL>: If the call is noreturn,
	remove a subsequent GOTO or RETURN statement.

From-SVN: r152959

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2aedb05..c05cc6d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,10 +1,15 @@
+2009-10-17  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gimple-low.c (lower_stmt) <GIMPLE_CALL>: If the call is noreturn,
+       remove a subsequent GOTO or RETURN statement.
+
 2009-10-17  Andy Hutchinson  <hutchinsonandy@aim.com>
 
        * config/avr.md (*movqi): Add zero as equally preferable constraint
        as general register.
-       (*movhi): Ditto. 
+       (*movhi): Ditto.
 
-       2009-10-17  Eric Botcazou  <ebotcazou@adacore.com>
+2009-10-17  Eric Botcazou  <ebotcazou@adacore.com>
 
        * print-tree.c (print_node): Fix string for DECL_STRUCT_FUNCTION.
 

diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c
index b58fd7b..39c7351 100644 (file)
--- a/gcc/gimple-low.c
+++ b/gcc/gimple-low.c
@@ -387,6 +387,19 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
            lower_builtin_setjmp (gsi);
            return;
          }
+
+       /* After a noreturn call, remove a subsequent GOTO or RETURN that might
+          have been mechanically added; this will prevent the EH lowering pass
+          from adding useless edges and thus complicating the initial CFG.  */
+       if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN))
+         {
+           gsi_next (gsi);
+           if (!gsi_end_p (*gsi)
+               && (gimple_code (gsi_stmt (*gsi)) == GIMPLE_GOTO
+                   || gimple_code (gsi_stmt (*gsi)) == GIMPLE_RETURN))
+             gsi_remove (gsi, false);
+           return;
+         }
       }
       break;
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1490061..62f8075 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-10-17  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gnat.dg/noreturn1.ad[sb]: New test.
+
 2009-10-17  Janus Weil  <janus@gcc.gnu.org>
            Paul Thomas  <pault@gcc.gnu.org>
 

diff --git a/gcc/testsuite/gnat.dg/noreturn1.adb b/gcc/testsuite/gnat.dg/noreturn1.adb
new file mode 100644 (file)
index 0000000..83eafe7
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/noreturn1.adb
@@ -0,0 +1,15 @@
+-- { dg-compile }
+
+package body Noreturn1 is
+
+   procedure Error (E : in Exception_Occurrence) is
+      Occurrence_Message : constant String := Exception_Message (E);
+   begin
+      if Occurrence_Message = "$" then
+         raise Program_Error;
+      else
+         raise Constraint_Error;
+      end if;
+   end;
+
+end Noreturn1;

diff --git a/gcc/testsuite/gnat.dg/noreturn1.ads b/gcc/testsuite/gnat.dg/noreturn1.ads
new file mode 100644 (file)
index 0000000..c63e439
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/noreturn1.ads
@@ -0,0 +1,8 @@
+with Ada.Exceptions; use Ada.Exceptions;
+
+package Noreturn1 is
+
+   procedure Error (E : in Exception_Occurrence);
+   pragma No_Return (Error);
+
+end Noreturn1;