backport: trans.c (Call_to_gnu): If this is a function call and there is no target...

	Backport from mainline
	2018-05-31  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/trans.c (Call_to_gnu): If this is a function call and
	there is no target, also create a temporary for the return value for
	an allocator if the type is an unconstrained record type with default
	discriminant.

From-SVN: r261105

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 67abd8fcf94c398e6ad39caf27d5f8c4c921264a..7f6106e0fbdfbb658982ae1332220f90f241712a 100644 (file)
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,13 @@
+2018-06-02  Eric Botcazou  <ebotcazou@adacore.com>
+
+       Backport from mainline
+       2018-05-31  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gcc-interface/trans.c (Call_to_gnu): If this is a function call and
+       there is no target, also create a temporary for the return value for
+       an allocator if the type is an unconstrained record type with default
+       discriminant.
+
 2018-03-06  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gcc-interface/trans.c (convert_with_check): Fix typo in the condition

diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index 245994181f34e70f9257ba70c45d6a5fc659c1e0..46d88fc8e28544a0c847f818a0749d4d4df90bc2 100644 (file)
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -4302,12 +4302,15 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
          because we need to preserve the return value before copying back the
          parameters.
 
-       2. There is no target and the call is made for neither an object nor a
+       2. There is no target and the call is made for neither an object, nor a
          renaming declaration, nor a return statement, nor an allocator, and
          the return type has variable size because in this case the gimplifier
-         cannot create the temporary, or more generally is simply an aggregate
-         type, because the gimplifier would then create the temporary in the
-         outermost scope instead of locally.
+         cannot create the temporary, or more generally is an aggregate type,
+         because the gimplifier would create the temporary in the outermost
+         scope instead of locally.  But there is an exception for an allocator
+         of an unconstrained record type with default discriminant because we
+         allocate the actual size in this case, unlike the other 3 cases, so
+         we need a temporary to fetch the discriminant and we create it here.
 
        3. There is a target and it is a slice or an array with fixed size,
          and the return type has variable size, because the gimplifier
@@ -4326,8 +4329,9 @@ Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target,
              && Nkind (Parent (gnat_node)) != N_Object_Declaration
              && Nkind (Parent (gnat_node)) != N_Object_Renaming_Declaration
              && Nkind (Parent (gnat_node)) != N_Simple_Return_Statement
-             && !(Nkind (Parent (gnat_node)) == N_Qualified_Expression
-                  && Nkind (Parent (Parent (gnat_node))) == N_Allocator)
+             && (!(Nkind (Parent (gnat_node)) == N_Qualified_Expression
+                   && Nkind (Parent (Parent (gnat_node))) == N_Allocator)
+                 || type_is_padding_self_referential (gnu_result_type))
              && AGGREGATE_TYPE_P (gnu_result_type)
              && !TYPE_IS_FAT_POINTER_P (gnu_result_type))
          || (gnu_target

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 95dfdec8e410e5f2914ecfe013c26489a4feb92d..e21528939c4230fcf3ad968a336a768ca3e0e0c7 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-02  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gnat.dg/discr53.ad[sb]: New test.
+       * gnat.dg/discr53_pkg.ads: New helper.
+
 2018-05-25  Steven G. Kargl  <kargl@gcc.gnu.org>
 
        PR fortran/85895

diff --git a/gcc/testsuite/gnat.dg/discr53.adb b/gcc/testsuite/gnat.dg/discr53.adb
new file mode 100644 (file)
index 0000000..2e362a7
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/discr53.adb
@@ -0,0 +1,19 @@
+--  { dg-do compile }
+
+package body Discr53 is
+
+   function F return Rec is
+      Data : Rec;
+   begin
+      return Data;
+   end;
+
+   type Ptr is access Rec;
+
+   procedure Proc is
+      Local : Ptr;
+   begin
+      Local := new Rec'(F);
+   end;
+
+end Discr53;

diff --git a/gcc/testsuite/gnat.dg/discr53.ads b/gcc/testsuite/gnat.dg/discr53.ads
new file mode 100644 (file)
index 0000000..3fa9f0f
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/discr53.ads
@@ -0,0 +1,16 @@
+with Discr53_Pkg;
+
+package Discr53 is
+
+   type Rec (D : Boolean := False) is record
+      case D is
+         when True  => S : String (1 .. Discr53_Pkg.Max);
+         when False => null;
+      end case;
+   end record;
+
+   function F return Rec;
+
+   procedure Proc;
+
+end Discr53;

diff --git a/gcc/testsuite/gnat.dg/discr53_pkg.ads b/gcc/testsuite/gnat.dg/discr53_pkg.ads
new file mode 100644 (file)
index 0000000..d36e1ba
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/discr53_pkg.ads
@@ -0,0 +1,5 @@
+package Discr53_Pkg is
+
+  function Max return Natural;
+
+end Discr53_Pkg;