d: Fix ICE Segmentation fault during RTL pass: expand on armhf/armel/s390x

gcc/d/ChangeLog:

	PR d/96301
	* decl.cc (DeclVisitor::visit (FuncDeclaration *)): Only return
	non-trivial structs by invisible reference.

gcc/testsuite/ChangeLog:

	PR d/96301
	* gdc.dg/pr96301a.d: New test.
	* gdc.dg/pr96301b.d: New test.
	* gdc.dg/pr96301c.d: New test.

4 files changed, 92 insertions, 6 deletions

diff --git a/gcc/d/decl.cc b/gcc/d/decl.cc
index 72c8a8c..295f780 100644
--- a/gcc/d/decl.cc
+++ b/gcc/d/decl.cc
@@ -958,11 +958,14 @@ public:
       {
 	tree resdecl = DECL_RESULT (fndecl);
 
-	TREE_TYPE (resdecl)
-	  = build_reference_type (TREE_TYPE (resdecl));
-	DECL_BY_REFERENCE (resdecl) = 1;
-	TREE_ADDRESSABLE (resdecl) = 0;
-	relayout_decl (resdecl);
+	/* Return non-trivial structs by invisible reference.  */
+	if (TREE_ADDRESSABLE (TREE_TYPE (resdecl)))
+	  {
+	    TREE_TYPE (resdecl) = build_reference_type (TREE_TYPE (resdecl));
+	    DECL_BY_REFERENCE (resdecl) = 1;
+	    TREE_ADDRESSABLE (resdecl) = 0;
+	    relayout_decl (resdecl);
+	  }
 
 	if (d->nrvo_var)
 	  {
@@ -972,7 +975,9 @@ public:
 	    DECL_NAME (resdecl) = DECL_NAME (var);
 	    /* Don't forget that we take its address.  */
 	    TREE_ADDRESSABLE (var) = 1;
-	    resdecl = build_deref (resdecl);
+
+	    if (DECL_BY_REFERENCE (resdecl))
+	      resdecl = build_deref (resdecl);
 
 	    SET_DECL_VALUE_EXPR (var, resdecl);
 	    DECL_HAS_VALUE_EXPR_P (var) = 1;
diff --git a/gcc/testsuite/gdc.dg/pr96301a.d b/gcc/testsuite/gdc.dg/pr96301a.d
new file mode 100644
index 0000000..314904b
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr96301a.d
@@ -0,0 +1,31 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96301
+// { dg-additional-options "-fPIC" { target fpic } }
+// { dg-do compile }
+struct Type
+{
+    size_t length;
+    int* ptr;
+}
+
+class Container
+{
+    Type children;
+
+    void remove(void* data)
+    {
+        Type remove(Type range)
+        {
+            auto result = range;
+            if (result.front)
+                return result;
+            assert(0);
+        }
+        if (data)
+            remove(children);
+    }
+}
+
+int front(Type a)
+{
+    return a.ptr[0];
+}
diff --git a/gcc/testsuite/gdc.dg/pr96301b.d b/gcc/testsuite/gdc.dg/pr96301b.d
new file mode 100644
index 0000000..3d978be
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr96301b.d
@@ -0,0 +1,25 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96301
+// { dg-additional-options "-fPIC" { target fpic } }
+// { dg-do compile }
+class Container
+{
+    int[100] children;
+
+    void remove(void* data)
+    {
+        int[100] remove(int[100] range)
+        {
+            auto result = range;
+            if (result.front)
+                return result;
+            assert(0);
+        }
+        if (data)
+            remove(children);
+    }
+}
+
+int front(int[100] a)
+{
+    return a.ptr[0];
+}
diff --git a/gcc/testsuite/gdc.dg/pr96301c.d b/gcc/testsuite/gdc.dg/pr96301c.d
new file mode 100644
index 0000000..c909462
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr96301c.d
@@ -0,0 +1,25 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96301
+// { dg-additional-options "-fPIC" { target fpic } }
+// { dg-do compile }
+class Container
+{
+    int[] children;
+
+    void remove(void* data)
+    {
+        int[] remove(int[] range)
+        {
+            auto result = range;
+            if (result.front)
+                return result;
+            assert(0);
+        }
+        if (data)
+            remove(children);
+    }
+}
+
+int front(int[] a)
+{
+    return a.ptr[0];
+}