* gimplify.c (gimplify_modify_expr_rhs): Use simple test on the size.

	* cgraph.c (cgraph_redirect_edge_call_stmt_to_callee): Do not remove
	the LHS of a no-return call if its type has variable size.
	* tree-cfgcleanup.c (fixup_noreturn_call): Likewise.
	* tree-cfg.c (verify_gimple_call): Accept these no-return calls.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@223997 138bc75d-0d04-0410-961f-82ee72b054a4

9 files changed, 85 insertions, 16 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a7f3071e913..a19528320f1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2015-06-01  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gimplify.c (gimplify_modify_expr_rhs): Use simple test on the size.
+	* cgraph.c (cgraph_redirect_edge_call_stmt_to_callee): Do not remove
+	the LHS of a no-return call if its type has variable size.
+	* tree-cfgcleanup.c (fixup_noreturn_call): Likewise.
+	* tree-cfg.c (verify_gimple_call): Accept these no-return calls.
+
 2015-06-01  Andreas Tobler  <andreast@gcc.gnu.org>
 
 	* read-rtl.c: Adapt to use HAVE_DECL_ATOLL instead of HAVE_ATOLL.
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 6a674db4078..2ded5af546e 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1464,8 +1464,10 @@ cgraph_edge::redirect_call_stmt_to_callee (void)
       update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);
     }
 
-  /* If the call becomes noreturn, remove the lhs.  */
-  if (lhs && (gimple_call_flags (new_stmt) & ECF_NORETURN))
+  /* If the call becomes noreturn, remove the LHS if possible.  */
+  if (lhs
+      && (gimple_call_flags (new_stmt) & ECF_NORETURN)
+      && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST)
     {
       if (TREE_CODE (lhs) == SSA_NAME)
 	{
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 2720d02f47a..58a60bfd62a 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -4341,7 +4341,8 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p,
 		/* It's OK to use the target directly if it's being
 		   initialized. */
 		use_target = true;
-	      else if (variably_modified_type_p (TREE_TYPE (*to_p), NULL_TREE))
+	      else if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p)))
+		       != INTEGER_CST)
 		/* Always use the target and thus RSO for variable-sized types.
 		   GIMPLE cannot deal with a variable-sized assignment
 		   embedded in a call statement.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8168fabd76c..09395da513c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-01  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/specs/varsize_return2.ads: New test.
+	* gnat.dg/specs/varsize_return2_pkg.ad[sb]: New helper.
+
 2015-06-01  Yuri Rumyantsev  <ysrumyan@gmail.com>
 
 	* gcc.dg/vect/vect-outer-simd-1.c: New test.
diff --git a/gcc/testsuite/gnat.dg/specs/varsize_return2.ads b/gcc/testsuite/gnat.dg/specs/varsize_return2.ads
new file mode 100644
index 00000000000..1f7d1a0d860
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/specs/varsize_return2.ads
@@ -0,0 +1,12 @@
+-- { dg-do compile }
+-- { dg-options "-O" }
+
+with Varsize_Return2_Pkg; use Varsize_Return2_Pkg;
+
+package Varsize_Return2 is
+
+   package My_G is new G (0);
+
+   Result : constant T := My_G.Get;
+
+end Varsize_Return2;
diff --git a/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.adb b/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.adb
new file mode 100644
index 00000000000..f37d2fafd6d
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.adb
@@ -0,0 +1,18 @@
+package body Varsize_Return2_Pkg is

+

+   function Len return Positive is

+   begin

+      return 4;

+   end;

+

+   package body G is

+

+      function Get return Small_T is

+      begin

+         raise Program_Error;

+         return Get;

+      end;

+

+   end G;

+

+end Varsize_Return2_Pkg;

diff --git a/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.ads b/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.ads
new file mode 100644
index 00000000000..1fe40b9b285
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/specs/varsize_return2_pkg.ads
@@ -0,0 +1,20 @@
+-- { dg-excess-errors "no code generated" }
+
+package Varsize_Return2_Pkg is
+
+   type T (D: Positive) is record
+      Data: String (1 .. D);
+   end record;
+
+   function Len return Positive;
+
+   generic
+      I : Integer;
+   package G is
+
+      subtype Small_T is T(Len);
+      function Get return Small_T;
+
+   end G;
+
+end Varsize_Return2_Pkg;
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 99b27c7dc97..c53cf3e76e9 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -3391,17 +3391,19 @@ verify_gimple_call (gcall *stmt)
        return true;
      }
 
-  if (gimple_call_lhs (stmt)
-      && (!is_gimple_lvalue (gimple_call_lhs (stmt))
-	  || verify_types_in_gimple_reference (gimple_call_lhs (stmt), true)))
+  tree lhs = gimple_call_lhs (stmt);
+  if (lhs
+      && (!is_gimple_lvalue (lhs)
+	  || verify_types_in_gimple_reference (lhs, true)))
     {
       error ("invalid LHS in gimple call");
       return true;
     }
 
-  if (gimple_call_ctrl_altering_p (stmt)
-      && gimple_call_lhs (stmt)
-      && gimple_call_noreturn_p (stmt))
+  if (lhs
+      && gimple_call_ctrl_altering_p (stmt)
+      && gimple_call_noreturn_p (stmt)
+      && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST)
     {
       error ("LHS in noreturn call");
       return true;
@@ -3409,19 +3411,18 @@ verify_gimple_call (gcall *stmt)
 
   fntype = gimple_call_fntype (stmt);
   if (fntype
-      && gimple_call_lhs (stmt)
-      && !useless_type_conversion_p (TREE_TYPE (gimple_call_lhs (stmt)),
-				     TREE_TYPE (fntype))
+      && lhs
+      && !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (fntype))
       /* ???  At least C++ misses conversions at assignments from
 	 void * call results.
 	 ???  Java is completely off.  Especially with functions
 	 returning java.lang.Object.
 	 For now simply allow arbitrary pointer type conversions.  */
-      && !(POINTER_TYPE_P (TREE_TYPE (gimple_call_lhs (stmt)))
+      && !(POINTER_TYPE_P (TREE_TYPE (lhs))
 	   && POINTER_TYPE_P (TREE_TYPE (fntype))))
     {
       error ("invalid conversion in gimple call");
-      debug_generic_stmt (TREE_TYPE (gimple_call_lhs (stmt)));
+      debug_generic_stmt (TREE_TYPE (lhs));
       debug_generic_stmt (TREE_TYPE (fntype));
       return true;
     }
diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index 26258aad1ef..562f5923614 100644
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -612,9 +612,11 @@ fixup_noreturn_call (gimple stmt)
 	}
     }
 
-  /* If there is an LHS, remove it.  */
+  /* If there is an LHS, remove it, but only if its type has fixed size.
+     The LHS will need to be recreated during RTL expansion and creating
+     temporaries of variable-sized types is not supported.  */
   tree lhs = gimple_call_lhs (stmt);
-  if (lhs)
+  if (lhs && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST)
     {
       gimple_call_set_lhs (stmt, NULL_TREE);