From: Eric Botcazou <ebotcazou@adacore.com>
Date: Sat, 26 Jan 2019 16:03:42 +0000 (+0000)
Subject: trans.c (gnat_to_gnu): Use DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT for the size... 
X-Git-Tag: releases/gcc-7.5.0~636
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3ba9569b7b2c3973ebf827febaa5fd827ada6755;p=thirdparty%2Fgcc.git

trans.c (gnat_to_gnu): Use DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT for the size to be assigned by a...

	* gcc-interface/trans.c (gnat_to_gnu) <N_Assignment_Statement>: Use
	DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT for the size to be assigned
	by a call to memset if the LHS is a DECL.

From-SVN: r268298
---

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index df465b9edb84..27719e695582 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,9 @@
+2019-01-26  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/trans.c (gnat_to_gnu) <N_Assignment_Statement>: Use
+	DECL_SIZE_UNIT instead of TYPE_SIZE_UNIT for the size to be assigned
+	by a call to memset if the LHS is a DECL.
+
 2019-01-26  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc-interface/trans.c (struct loop_info_d): Remove artificial field.
diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index 25bae750fbbb..c2c385d70308 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -6904,21 +6904,29 @@ gnat_to_gnu (Node_Id gnat_node)
 	  /* Or else, use memset when the conditions are met.  */
 	  else if (use_memset_p)
 	    {
-	      tree value = fold_convert (integer_type_node, gnu_rhs);
-	      tree to = gnu_lhs;
-	      tree type = TREE_TYPE (to);
-	      tree size
-	        = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (type), to);
-	      tree to_ptr = build_fold_addr_expr (to);
+	      tree value
+		= real_zerop (gnu_rhs)
+		  ? integer_zero_node
+		  : fold_convert (integer_type_node, gnu_rhs);
+	      tree dest = build_fold_addr_expr (gnu_lhs);
 	      tree t = builtin_decl_explicit (BUILT_IN_MEMSET);
-	      if (TREE_CODE (value) == INTEGER_CST)
+	      /* Be extra careful not to write too much data.  */
+	      tree size;
+	      if (TREE_CODE (gnu_lhs) == COMPONENT_REF)
+		size = DECL_SIZE_UNIT (TREE_OPERAND (gnu_lhs, 1));
+	      else if (DECL_P (gnu_lhs))
+		size = DECL_SIZE_UNIT (gnu_lhs);
+	      else
+		size = TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs));
+	      size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_lhs);
+	      if (TREE_CODE (value) == INTEGER_CST && !integer_zerop (value))
 		{
 		  tree mask
 		    = build_int_cst (integer_type_node,
 				     ((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1);
 		  value = int_const_binop (BIT_AND_EXPR, value, mask);
 		}
-	      gnu_result = build_call_expr (t, 3, to_ptr, value, size);
+	      gnu_result = build_call_expr (t, 3, dest, value, size);
 	    }
 
 	  /* Otherwise build a regular assignment.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index dfa212eafdeb..acb417983cdd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2019-01-26  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/array34.adb: New test.
+
 2019-01-26  Dominique d'Humieres  <dominiq@gcc.gnu.org>
 
 	PR fortran/85579
diff --git a/gcc/testsuite/gnat.dg/array34.adb b/gcc/testsuite/gnat.dg/array34.adb
new file mode 100644
index 000000000000..62809cd02691
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/array34.adb
@@ -0,0 +1,22 @@
+--  { dg-do run }
+
+procedure Array34 is
+
+  type Arr is array (1 .. 6) of Short_Short_Integer;
+  for Arr'Alignment use 4;
+
+  type Rec is record
+    A : Arr;
+    B: Short_Integer;
+  end record;
+  pragma Pack (Rec);
+
+  R : Rec;
+
+begin
+  R.B := 31415;
+  R.A := (others => 0);
+  if R.B /= 31415 then
+    raise Program_Error;
+  end if;
+end;