[Ada] Do not generate useless temporary for allocator

[Ada] Do not generate useless temporary for allocator

[Eric Botcazou]

[-- Attachment #1: Type: text/plain, Size: 433 bytes --]

This is a regression present on the mainline, 7 and 6 branches: the compiler 
generates an useless temporary for an allocator.

Tested on x86_64-suse-linux, applied on mainline, 7 and 6 branches.


2017-09-05  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/trans.c (Call_to_gnu): If this is a function call and
	there is no target, do not create a temporary for the return value for
	an allocator either.

-- 
Eric Botcazou

[-- Attachment #2: p.diff --]
[-- Type: text/x-patch, Size: 1638 bytes --]

Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c	(revision 251691)
+++ gcc-interface/trans.c	(working copy)
@@ -4338,11 +4338,11 @@ Call_to_gnu (Node_Id gnat_node, tree *gn
 	  parameters.
 
        2. There is no target and the call is made for neither an object nor a
-	  renaming declaration, nor a return statement, 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 create the temporary in the outermost scope instead
-	  of locally.
+	  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.
 
        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
@@ -4361,6 +4361,8 @@ Call_to_gnu (Node_Id gnat_node, tree *gn
 	      && 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)
 	      && AGGREGATE_TYPE_P (gnu_result_type)
 	      && !TYPE_IS_FAT_POINTER_P (gnu_result_type))
 	  || (gnu_target